Appendix A: Support Information¶
A.1 Questions and Information¶
The URL for the CLIPS Web page is http://clipsrules.sourceforge.net.
Questions regarding CLIPS can be posted to one of several online forums including the CLIPS Expert System Group, http://groups.google.com/group/CLIPSESG/, the SourceForge CLIPS Forums, http://sourceforge.net/forum/?group_id=215471, and Stack Overflow, http://stackoverflow.com/questions/tagged/clips.
Inquiries related to the use or installation of CLIPS can be sent via electronic mail to clipssupport@secretsocietysoftware.com.
A.2 Documentation¶
The CLIPS Reference Manuals and User?s Guide are available in Portable Document Format (PDF) at http://clipsrules.sourceforge.net/OnlineDocs.html.
Expert Systems: Principles and Programming, 4th Edition, by Giarratano and Riley comes with a CD-ROM containing CLIPS 6.22 executables (DOS, Windows XP, and Mac OS), documentation, and source code. The first half of the book is theory oriented and the second half covers rule-based, procedural, and object-oriented programming using CLIPS.
A.3 CLIPS Source Code and Executables¶
CLIPS executables and source code are available on the SourceForge web site at http://sourceforge.net/projects/clipsrules/files.
Appendix B: Update Release Notes ====================
The following sections denote the changes and bug fixes for CLIPS versions 6.2. 6.21, 6.22, 6.23, 6.24, and 6.3.
B.1 Version 6.30¶
?E**Performance Improvements** ?ERule performance has been improved particularly in situations with large numbers of fact/instances or partial matches.
?E**64-bit Integers** ?EIntegers in CLIPS are now represented using the ?long long?EC data type which provides a minimum of 64 bits of precision.
?E**Reset after Clear** ?EA reset command is now performed after a clear command (which includes the clear command issued internally by CLIPS when it is started). Since no user constructs will be present after a clear, the primary effect of this behavior is to create the initial-fact and initial-object.
?E**Pattern Addition** ?EThe initial-fact and initial-object patterns are no longer used in triggering rules. When printing partial matches, the * symbol is used to indicate a not or exists pattern that is satisfied.
?E**Module Specifiers** ?EA module specifier can be used in expressions to reference a deffunction or defgeneric that is exported by a module, but not specifically imported by the module which is referencing it. For example: (UTIL::my-function a 3).
?E**Instance Name and Class Visibility** ?EInstance names now have global scope and must be unique regardless of their module. Instances of classes that are not in scope can be created if the module name is specified as part of the class name. Messages can be sent to instances regardless of whether the instance class is in scope.
?E**Command Prompt** ?ELocal variables bound at the command prompt using the bind function persist until a reset or clear command is issued (see section 2.1.1).
?E**Printout Function** ?EThe deprecated use of the symbol t as a substitute for the crlf symbol is no longer allowed.
?E**MicroEMACS Editor** ?EThe built-in editor is no longer supported.
?E**New Functions and Commands** - Several new functions and commands have been added. They are:
?E**foreach** (see section 12.6.10)
?E**operating-system** (see section 12.7.12)
?E**Command and Function Changes** - The following commands and functions have been enhanced:
?E**matches** (see section 13.6.4). This command now has a return value indicating the number of matches, partial matches, and activations. The amount of output can be controlled with a verbosity argument.
?E**open** (see section 12.4.2.1). The r+ mode is no longer supported. New modes ab and rb have been added.
?E**Help Functions** ?EThe help and help-path funtions are no longer supported
?E**Behavior Changes** - The following changes have been made to behavior:
?EA defgeneric redefinition warning is no longer printed when a defmethod is defined.
B.2 Version 6.24¶
?E**Allowed Classes Constraint Attribute** ?EThe allowed-classes constraint attribute allows a slot containing an instance value to be restricted to the specified list of classes.
?E**New Functions and Commands** - Several new functions and commands have been added. They are:
?E**deftemplate-slot-allowed-values**
?E**deftemplate-slot-cardinality**
?E**deftemplate-slot-defaultp**
?E**deftemplate-slot-default-value**
?E**deftemplate-slot-existp**
?E**deftemplate-slot-multip**
?E**deftemplate-slot-names**
?E**deftemplate-slot-range**
?E**deftemplate-slot-singlep**
?E**deftemplate-slot-type**
?E**get-char**
?E**get-region**
?E**ppfact**
?E**read-number**
?E**set-locale**
?E**slot-allowed-classes**
?E**Command and Function Changes** - The following commands and functions have been enhanced:
?E**format** The formatting of printed numbers can be changed to use a native locale with the set-locale function. The documentation has been updated to include the effect of the precision argument on the d, g, o, and x format flags.
?E**Behavior Changes** - The following changes have been made to behavior:
?EThe message displayed when a construct is redefined and compilations are being watched is now more prominent.
?E**Bug Fixes** - The following bugs were fixed by the 6.24 release:
?EThe DescribeClass macros were incorrectly defined.
?EThe sort function leaks memory when called with a multifield value of length zero.
?ELink error occurred for the SlotExistError function when OBJECT_SYSTEM is set to 0 in setup.h.
?EAn error when calling the Eval function causes a subsequent call to DeallocateEnvironmentData to fail.
?ELoading a binary instance file from a run-time program caused a bus error.
?EIncorrect activations could occur with the exists CE.
?ECompilation errors occurred when compiling CLIPS source as C++ files.
?EThe AssignFactSlotDefaults function did not correctly handle defaults for multifield slots.
?EThe slot-default-value function crashed when no default existed for a slot (the ?NONE value was specified).
?ECLIPS crashed on AMD64 processor in the function used to generate hash values for integers.
?EA syntax error was not generated for the last deffunction or defmethod in a file if it was missing the final closing right parenthesis.
?E**Compiler Support** - The following compilers are now supported. See the Interfaces Guide for more details.
?EMetrowerks CodeWarrior 9.6 for Mac OS X.
?EXcode 2.3 for Mac OS X.
?EMicrosoft Visual C++ .NET 2003 for Windows.
B.3 Version 6.23¶
?E**Fact-Set Query Functions** ?ESix new functions similar to the instance set query functions have been added for determining and performing actions on sets of facts that satisfy user-defined queries: any-factp, find-fact, find-all-facts, do-for-fact, do-for-all-facts, and delayed-do-for-all-facts. The GetNextFactInTemplate function allows iteration from C over the facts belonging to a specific deftemplate.
?E**Bug Fixes** - The following bugs were fixed by the 6.23 release:
?EPassing the wrong number of arguments to a deffunction through the funcall function could cause unpredictable behavior including memory corruption.
?EA large file name (at least 60 characters) passed into the fetch command causes a buffer overrun.
?EA large file name (at least 60 characters) passed into the constructs-to-c command causes a buffer overrun.
?EA large defclass or defgeneric name (at least 500 characters) causes a buffer overrun when the profile-info command is called.
?EA large module or construct name (at least 500 characters) causes a buffer overrun when the get-<construct>-list command is called.
?EThe FalseSymbol and TrueSymbol constants were not defined as described in the Advanced Programming Guide. These constants have have now been defined as macros so that their corresponding environment companion functions (EnvFalseSymbol and EnvTrueSymbol) could be defined. See the Advanced Programming Guide for more details.
?EThe slot-writablep function returns TRUE for slots having initialize-only access.
?EFiles created by the constructs-to-c function for use in a run-time program generate compilation errors.
?E**Command and Function Changes** - The following commands and functions have been enhanced:
?E**funcall** Multifield arguments are no longer expanded into multiple arguments before being passed to the target function of the funcall. The expand$ function can be placed around an argument to revert to the old behavior.
?E**Compiler Support** - The following compilers are now supported. See the Interfaces Guide for more details.
?EMetrowerks CodeWarrior 9.4 for Mac OS X and Windows.
?EXcode 1.2 for Mac OS X.
B.4 Version 6.22¶
?E**Bug Fixes** - The following bugs were fixed by the 6.22 release:
?ENumerous fixes for functions and macros that did not accept the correct number of arguments as specified in the Advanced Programming Guide. The following functions and macros were corrected: Agenda, BatchStar, EnvGetActivationSalience, EnvBatchStar, EnvFactDeftemplate, EnvFactExistp, EnvFactList, EnvFactSlotNames, EnvGetNextInstanceInClassAndSubclasses, EnvLoadInstancesFromString, EnvRestoreInstancesFromString, EnvSetOutOfMemoryFunction, FactDeftemplate, FactExistp, FactList, FactSlotNames, GetNextInstanceInClassAndSubclasses, LoadInstancesFromString, RestoreInstancesFromString, SetOutOfMemoryFunction.
B.5 Version 6.21¶
?E**Bug Fixes** - The following bugs were fixed by the 6.21 release:
?EThe C GetDefglobalValue macro did not have the correct number of arguments.
?EThe C RtnArgCount macro did not have the correct number of arguments.
?EErroneous error generated for object pattern under some circumstances.
?EThe C Save macro did not have the correct number of arguments.
?EThe C Eval and Build functions did not have the correct number of arguments.
?EThe progn$ index variable did not always return the correct value.
?EThe member$ function did not always return the correct value.
?EC++ style comments in the code caused errors when using strict ANSI C compilation.
?EThe C LoadFactsFromString function did not have the correct number of arguments.
?EPrior bug fix to the PutFactSlot C function prevented memory associated with the fact to be garbage collected after the fact had been retracted. The original bug is now fixed through a new API which allows embedded programs to temporarily disable garbage collection. See section 1.4 of The Advanced Programming Guide for more details.
B.6 Version 6.2¶
?EEnvironments ?EIt is now possible in an embedded application to create multiple environments into which programs can be loaded. See section 9 of The Advanced Programming Guide for more details
?E**New Microsoft Windows and MacOS X Interfaces** ?EAn improved Windows 95/98/NT CLIPS interface is now available for PC compatible computers. See section 2 of The Interfaces Guide for more details. An improved MacOS X/9.0 CLIPS interface is now available for Macintosh computers. See section 3 of The Interfaces Guide for more details.
?E**COOL Default Behavior** ?EFor the purpose of role inheritance, system defined classes behave as concrete classes. The default value for the create-accessor facet is now read-write. For the purpose of pattern-match inheritance, system defined classes behave as reactive classes unless the inheriting class is abstract. This behavior can be restored to CLIPS 6.1 behavior using the set-class-defaults-mode function.
?E**COOL Changes** - The following changes have been made to instance behavior:
?ENewly created instances are sent a create message.
?E**New Functions and Commands** - Several new functions and commands have been added. They are:
?E**funcall**
?E**get-class-defaults-mode**
?E**set-class-defaults-mode**
?E**string-to-field**
?E**timer**
?E**Command and Function Enhancements** - The following commands and functions have been enhanced:
?E**switch** The requirement of having at least two case statements has been removed.
?E**printout** The logical name nil now has special significance.
?E**sort** Multifield as well as single-field values can now be sorted.
?E**random** The integer value returned by the function can now be restricted to a specified range of values.
?E**do-for-instance** Multiple actions can be specified in the action portion of the query (which previously required an explicit progn call).
?E**do-for-all-instances** Multiple actions can be specified in the action portion of the query (which previously required an explicit progn call).
?E**delayed-do-for-all-instances** Multiple actions can be specified in the action portion of the query (which previously required an explicit progn call).
?E**Bug Fixes** - The following bugs were fixed by the 6.20 release:
?EInner member variables in nested instance set queries could be confused with member variables from an outer query. This would happen if the inner member variable name shared all of its characters with the first N characters of the outer variable name.
?ESome data structures generated by object pattern matching were not garbage collected until a run command was issued.
?EBackspaces were not properly handled in the display window of the Windows interface.
?EThe module name was not specified for deffunctions by the save command.
?EGarbage collection triggered by evaluating the arguments to str-cat/sym-cat could change the value of the arguments already retrieved.
?EThe PutFactSlot C function does not properly increment/decrement the slot value that it changes.
?EDefrule data structures could end up in an invalid state during a retract if a fact/object matched two patterns in a rule and one pattern was inside two nested not conditional elements and the other pattern was inside one not conditional element.
?EThe implode$ function does not properly handle the \ character in a string.
?EGarbage collection triggered by expression evaluation during an assert-string call could corrupt the fact being asserted.
?EInappropriate fact syntax for the assert-string function causes a crash.
?EThe evaluation error flag was not reset before calling the AssertString C function.
?EThe FindDefclass C function crashes when the specified module is not defined.
?EThe save command did not always properly save constructs when modules using import/export specifications were used.
Appendix C: Glossary ===========
This section defines some of the terminology used throughout this manual.
| abstraction | The definition of new classes to describe the common properties and behavior of a group of objects. |
| action | A function executed by a construct (such as the RHS of a rule) which typically has no return value, but performs some useful action (such as the printout action) (see section 12). |
| activation | A rule is activated if all of its conditional elements are satisfied and it has not yet fired based on a specific set of matching pattern entities that caused it to be activated. Note that a rule can be activated by more than one set of pattern entities. An activated rule that is placed on the agenda is called an activation. |
| active instance | The object responding to a message which can be referred to by ?self in the message?s handlers. |
| agenda | A list of all rules that are presently ready to fire. It is sorted by salience values and the current conflict resolution strategy. The rule at the top of the agenda is the next rule that will fire. |
| antecedent | The LHS of a rule. |
| bind | The action of storing a value in a variable. |
| class | Template for describing the common properties (slots) and behavior (message-handlers) of a group of objects called instances of the class. |
| class precedence list | A linear ordering of classes which describes the path of inheritance for a class. |
| command | A function executed at the top-level command prompt (such as the reset command) typically having no return value. |
| command prompt | In the interactive interface, the ?CLIPS>?Eprompt which indicates that CLIPS is ready for a command to be entered. |
| condition | A conditional element. |
| conditional | A restriction on the LHS of a rule which must be satisfied in order for the rule to be applicable (also referred to as a CE). |
| element |
| conflict resolution | A method for determining the order in which rules should fire among rules with the same salience. There are seven different conflict resolution strategies: depth, breadth, simplicity, complexity, lex, mea, and random. |
| strategy |
| consequent | The RHS of a rule. |
| constant | A non-varying single field value directly expressed as a series of characters. |
| constraint | In patterns, a constraint is a requirement that is placed on the value of a field from a fact or instance that must be satisified in order for the pattern to be satisfied. For example, the ~red constraint is satisfied if the field to which the constraint is applied is not the symbol red. The term constraint is also used to refer to the legal values allowed in the slots of facts and instances. |
| construct | A high level CLIPS abstraction used to add components to the knowledge base. |
| current focus | The module from which activations are selected to be fired. |
| current module | The module to which newly defined constructs that do not have a module specifier are added. Also is the default module for certain commands which accept as an optional argument a module name (such as list-defrules). |
| daemon | A message-handler which executes implicitly whenever some action is taken upon an object, such as initialization, deletion, or slot access. |
| deffunction | A non-overloaded function written directly in CLIPS. |
| deftemplate fact | A deftemplate name followed by a list of named fields (slots) and specific values used to represent a deftemplate object. Note that a deftemplate fact has no inheritance. Also called a non-ordered fact. |
| deftemplate object | An informal term for the entity described by a deftemplate. A deftemplate object is simply an informal term for the collections of slots (without specific values) which define a deftemplate. Deftemplate objects do not have inheritance |
| deftemplate pattern | A list of named constraints (constrained slots). A deftemplate pattern describes the attributes and associated values of a deftemplate object. Also called a non-ordered pattern. |
| delimiter | A character which indicates the end of a symbol. The following characters act as delimiters: any non-printable ASCII character (including spaces, tabs, carriage returns, and line feeds), a double quote, opening and closing parenthesis ?E?Eand ?E?E an ampersand ?E?E a vertical bar ?|?E a less than ?E?E a semicolon ?E?E and a tilde ?~?E |
| dynamic binding | The deferral of which message-handlers will be called for a message until run-time. |
| encapsulation | The requirement that all manipulation of instances of user-defined classes be done with messages. |
| expression | A function call with arguments specified. |
| external-address | The address of an external data structure returned by a function (written in a language such as C or Ada) that has been integrated with CLIPS (see section 2.3.1 for more details). |
| external function | A function written in an external language (such as C or Ada) defined by the user or provided by CLIPS and called from within CLIPS rules. |
| facet | A component of a slot specification for a class, e.g. default value and cardinality. |
| fact | An ordered or deftemplate (non-ordered) fact. Facts are the data about which rules rea?son and represent the current state of the world. |
| fact-address | A pointer to a fact obtained by binding a variable to the fact which matches a pattern on the LHS of a rule. |
| fact-identifier | A shorthand notation for referring to a fact. It consists of the character ?f?E followed by a dash, followed by the fact-index of the fact. |
| fact-index | A unique integer index used to identify a particular fact. |
| fact-list | The list of current facts. |
| field | A placeholder (named or unnamed) that has a value. |
| fire | A rule is said to have fired if all of its conditions are satisfied and the actions then are executed. |
| float | A number that begins with an optional sign followed optionally in order by zero or more digits, a decimal point, zero or more digits, and an exponent (consisting of an e or E followed by an integer). A floating point number must have at least one digit in it (not including the exponent) and must either contain a decimal point or an exponent (see section 2.3.1 for more details). |
| focus | As a verb, refers to changing the current focus. As a noun, refers to the current focus. |
| focus stack | The list of modules that have been focused upon. The module at the top of the focus stack is the current focus. When all the activations from the current focus have been fired, the current focus is removed from the focus stack and the next module on the stack becomes the current focus. |
| function | A piece of executable code identified by a specific name which returns a useful value or performs a useful side effect. Typically only used to refer to functions which do return a value (whereas commands and actions are used to refer to functions which do not return a value). |
| generic dispatch | The process whereby applicable methods are selected and executed for a particular generic function call. |
| generic function | A function written in CLIPS which can do different things depending on what the number and types of its arguments. |
| inference engine | The mechanism provided by CLIPS which automatically matches patterns against the current state of the fact-list and list of instances and determines which rules are applicable. |
| inheritance | The process whereby one class can be defined in terms of other class(es). |
| instance | An object is an instance of a class. Throughout the documentation, the term instance usually refers to objects which are instances of user-defined classes. |
| instance (of a user-defined class) | An object which can only be manipulated via messages, i.e all objects except symbols, strings, integers, floats, multifields and external-addresses. |
| instance-address | The address of an instance of a user-defined class (see section 2.3.1 for more details). |
| instance-name | A symbol enclosed within left and right brackets (see section 2.3.1 for more details). An instance-name refers to an object of the specified name which is an instance of a user-defined class. |
| instance-set | An ordered collection of instances of user-defined classes. Each member of an instance-set is an instance of a set of classes, where the set can be different for each member. |
| instance-set distributed action | A user-defined expression which is evaluated for every instance-set which satisfies an instance-set query. |
| instance-set query | A user-defined boolean expression applied to an instance-set to see if it satisfies further user-defined criteria. |
| integer | A number that begins with an optional sign followed by one or more digits (see section 2.3.1 for more details). |
| LHS | Left-Hand Side. The set of conditional elements that must be satisfied for the ac?tions of the RHS of a rule to be performed. |
| list | A group of items with no implied order. |
| logical name | A symbolic name that is associated with an I/O source or destination. |
| message | The mechanism used to manipulate an object. |
| message dispatch | The process whereby applicable message-handlers are selected and executed for a particular message. |
| message-handler | An implementation of a message for a particular class of objects. |
| message-handler precedence | The property used by the message dispatch to select between handlers when more than one is applicable to a particular message. |
| method | An implementation of a generic function for a particular set of argument restrictions. |
| method index | A shorthand notation for referring to a method with a particular set of parameter restrictions. |
| method precedence | The property used by the generic dispatch to select a method when more than one is applicable to a particular generic function call. |
| module | A workspace where a set of constructs can be grouped together such that explicit control can be maintained over restricting the access of the constructs by other modules. Also used to control the flow of execution of rules through the use of the focus command. |
| module specifier | A notation for specifying a module. It consists of a module name followed by two colons. When placed before a construct name, it?s used to specify which module a newly defined construct is to be added to or to specify which construct a command will affect if that construct is not in the current module. |
| multifield | A sequence of unnamed placeholders each having a value. |
| multifield value | A sequence of zero or more single-field values. |
| non-ordered fact | A deftemplate fact. |
| number | An integer or float. |
| object | A symbol, a string, a floating-point or integer number, a multifield value, an external address or an instance of a user-defined class. |
| order | Position is significant. |
| ordered fact | A sequence of unnamed fields. |
| ordered pattern | A sequence of constraints. |
| overload | The process whereby a generic function can do different things depending on the types and number of its arguments, i.e. the generic function has multiple methods. |
| pattern | A conditional element on the LHS of a rule which is used to match facts in the fact-list. |
| pattern entity | An item that is capable of matching a pattern on the LHS of a rule. Facts and instances are the only types of pattern entities available. |
| pattern-matching | The process of matching facts or instances to patterns on the LHS of rules. |
| polymorphism | The ability of different objects to respond to the same message in a specialized manner. |
| primitive type object | A symbol, string, integer, float, multifield or external-address. |
| relation | The first field in a fact or fact pattern. Synonomous with the associated deftemplate name. |
| RHS | Right-Hand Side. The actions to be performed when the LHS of a rule is satisfied. |
| rule | A collection of conditions and actions. When all patterns are satisfied, the actions will be taken. |
| salience | A priority number given to a rule. When multiple rules are ready for firing, they are fired in order of priority. The default salience is zero (0). Rules with the same salience are fired according to the current conflict resolution strategy. |
| sequence | An ordered list. |
| shadowed message-handler | A message-handler that must be explicitly called by another message-handler in order to execute. |
| shadowed method | A method that must be explicitly called by another method in order to execute. |
| single-field value | One of the primitive data types: float, integer, symbol, string, external-address, instance-name, or instance-address. |
| slot | Named single-field or multifield. To write a slot give the field name (attribute) followed by the field value. A single-field slot has one value, while a multifield slot has zero or more values. Note that a multifield slot with one value is strictly not the same as a single field slot. However, the value of a single-field slot (or variable) may match a multifield slot (or multifield variable) that has one field. |
| slot-accessor | Implicit message-handlers which provide read and write access to slots of an object. |
| specificity (class) | A class that precedes another class in a class precedence list is said to be more specific. A class is more specific than any of its superclasses. |
| specificity (rule) | A measure of how ?specific?Ethe LHS of a rule is in the pattern-matching process. The specificity is determined by the number of constants, variables, and function calls used within LHS conditional elements. |
| string | A set of characters that starts with double quotes (“) and is followed by zero or more printable characters and ends with double quotes (see section 2.3.1 for more details). |
| subclass | If a class inherits from a second class, the first class is a subclass of the second class. |
| superclass | If a class inherits from a second class, the second class is a superclass of the first class. |
| symbol | Any sequence of characters that starts with any printable ASCII character and is followed by zero or more characters (see section 2.3.1 for more details). |
| top level | In the interactive interface, the ?CLIPS>?Eprompt which indicates that CLIPS is ready for a command to be entered. |
| value | A single or multifield value. |
| variable | An symbolic location which can store a value. |
Appendix D: Performance Considerations ==========================
This appendix explains various techniques that the user can apply to a CLIPS program to maximize performance. Included are discussions of pattern ordering in rules, use of deffunctions in lieu of non-overloaded generic functions, parameter restriction ordering in generic function methods, and various approaches to improving the speed of message-passing and reading slots of instances.
D.1 Ordering of Patterns on the LHS¶
The issues which affect performance of a rule-based system are considerably different from those which affect conventional programs. This section discusses the single most important issue: the ordering of patterns on the LHS of a rule.
CLIPS is a rule language based on the RETE algorithm. The RETE algorithm was de?signed specifically to provide very efficient pattern-matching. CLIPS has attempted to implement this algorithm in a manner that combines efficient performance with powerful features. When used properly, CLIPS can provide very reasonable performance, even on microcomputers. However, to use CLIPS properly requires some under?stand?ing of how the pattern-matcher works.
Prior to initiating execution, each rule is loaded into the system and a network of all patterns that appear on the LHS of any rule is constructed. As facts and instances of reactive classes (referred to collectively as pattern entities) are created, they are filtered through the pattern network. If the pattern entities match any of the patterns in the network, the rules associated with those patterns are partially instantiated. When pattern entities exist that match all patterns on the LHS of the rule, variable bindings (if any) are considered. They are considered from the top to the bottom; i.e., the first pattern on the LHS of a rule is con?sidered, then the second, and so on. If the variable bindings for all patterns are consis?tent with the constraints applied to the variables, the rules are activated and placed on the agenda.
This is a very simple description of what occurs in CLIPS, but it gives the basic idea. A number of important considerations come out of this. Basic pattern-matching is done by filtering through the pattern network. The time involved in doing this is fairly constant. The slow portion of basic pattern-matching comes from comparing variable bindings across patterns. Therefore, the single most important performance factor is the ordering of patterns on the LHS of the rule. Unfortunately, there are no hard and fast methods that will al?ways order the patterns properly. At best, there seem to be three ?quasi?Emethods for ordering the patterns.
1) Most specific to most general. The more wildcards or unbound variables there are in a pattern, the lower it should go. If the rule firing can be controlled by a single pattern, place that pattern first. This technique often is used to provide control structure in an expert system; e.g., some kind of ?phase?Efact. Putting this kind of pattern first will guarantee that the rest of the rule will not be considered until that pattern exists. This is most effective if the single pattern consists only of literal constraints. If multiple patterns with variable bindings control rule firing, arrange the patterns so the most important variables are bound first and compared as soon as possible to the other pattern constraints. The use of phase facts is not recommended for large programs if they are used solely for controlling the flow of execution (use modules instead).
2) Patterns with the lowest number of occurrences in the fact-list or instance-list should go near the top. A large number of patterns of a particular form in the fact-list or instance-list can cause numerous partial instantiations of a rule that have to be ?weeded?Eout by comparing the variable bindings, a slower operation.
3) Volatile patterns (ones that are retracted and asserted continuously) should go last, particularly if the rest of the patterns are mostly independent. Every time a pattern entity is created, it must be filtered through the network. If a pattern entity causes a partial rule instan?tiation, the variable bindings must be considered. By putting volatile patterns last, the variable bindings only will be checked if all of the rest of the patterns already exist.
These rules are not independent and commonly conflict with each other. At best, they provide some rough guidelines. Since all systems have these characteristics in different proportions, at a glance the most efficient manner of ordering patterns for a given system is not evident. The best approach is to develop the rules with minimal consideration of ordering. When the reasoning is fairly well verified, experiment with the patterns until the optimum configuration is found.
Another performance issue is the use of multifield variables and wildcards ($?). Although they provide a powerful capability, they must be used very carefully. Since they can bind to zero or more fields, they can cause multiple instantiations of a single rule. In particular, the use of multiple multifield variables in one pattern can cause a very large number of instantiations.
Some final notes on rule performance. Experience suggests that the user should keep the expert system ?lean and mean.?EThe list of pattern entities should not be used as a data base for storage of ex?traneous information. Store and pattern-match only on that information necessary for reasoning. Keep the pattern-matching to a minimum and be as specific as possible. Many short, simple rules perform better than long, complex rules and have the added benefit of being easier to understand and maintain.
D.2 Deffunctions versus Generic Functions¶
Deffunctions execute more quickly than generic function because generic functions must first examine their arguments to determine which methods are applicable. If a generic function has only one method, a deffunction probably would be better. Care should be taken when determining if a particular function truly needs to be overloaded. In addition, if recompiling and relinking CLIPS is not prohibitive, user-defined external functions are even more efficient than deffunctions. This is because deffunction are interpreted whereas external functions are directly executed. For more details, see sections 7 and 8.2.
D.3 Ordering of Method Parameter Restrictions¶
When the generic dispatch examines a generic function?s method to determine if it is applicable to a particular set of arguments, it examines that method?s parameter restrictions from left to right. The programmer can take advantage of this by placing parameter restrictions which are less frequently satisfied than others first in the list. Thus, the generic dispatch can conclude as quickly as possible when a method is not applicable to a generic function call. If a group of restrictions are all equally likely to be satisfied, placing the simpler restrictions first, such as those without queries, will also allow the generic dispatch to conclude more quickly for a method that is not applicable. For more details, see section 8.4.3.
D.4 Instance-Addresses versus Instance-Names¶
COOL allows instances of user-defined classes to be referenced either by address or by name in functions which manipulate instances, such as message-passing with the send function. However, when an instance is referenced by name, CLIPS must perform an internal lookup to find the instance-address anyway. If the same instance is going to be manipulated many times, it might be advantageous to store the instance-address and use that as a reference. This will allow CLIPS to always go directly to the instance. For more details, see sections 2.4.2 and 12.16.4.6.
D.5 Reading Instance Slots Directly¶
Normally, message-passing must be used to read or set a slot of an instance. However, slots can be read directly within instance-set queries and message-handlers, and they can be set directly within message-handlers. Accessing slots directly is significantly faster than message-passing. Unless message-passing is required (because of slot daemons), direct access should be used when allowed. For more details, see sections 9.4.2, 9.4.3, 9.4.4, 9.6.3, 9.6.4 and 9.7.3.
Appendix E: CLIPS Warning Messages ======================
CLIPS typically will display two kinds of warning messages: those associated with executing constructs and those associated with loading constructs. This appendix describes some of the more common warning messages and what they mean. Each message begins with a unique identifier enclosed in brackets followed by the keyword WARNING; the messages are listed here in alphabetic order according to the identifier.
[CONSCOMP1] WARNING: Base file name exceeds 3 characters.
This may cause files to be overwritten if file name length
is limited on your platform.
The constructs-to-c command generates file names using the file name prefix supplied as an argument. If this base file name is longer than three characters, then the possibility exists that files may be overwritten if file name length is limited on your platform.
[CONSCOMP2] WARNING: Array name <arrayName> exceeds 6 characters in length. This variable may be indistinguishable from another by the linker.
The constructs-to-c command generates arrays for storing data structures. If the SHORT_LINK_NAMES compiler flag is enabled, then this warning message is displayed if generated array names exceed six characters in length.
[CSTRCPSR1] WARNING: Redefining <constructType>: <constructName>
This indicates that a previously defined construct of the specified type has been redefined.
[CSTRNBIN1] WARNING: Constraints are not saved with a binary image when dynamic constraint checking is disabled
or
[CSTRNCMP1] WARNING: Constraints are not saved with a constructs-to-c image when dynamic constraint checking is disabled
These warnings occur when dynamic constraint checking is disabled and the constructs-to-c or bsave commands are executed. Constraints attached to deftemplate and defclass slots will not be saved with the runtime or binary image in these cases since it is assumed that dynamic constraint checking is not required. Enable dynamic constraint checking with the set-dynamic-constraint-checking function before calling constructs-to-c or bsave in order to include constraints in the runtime or binary image.
[DFFNXFUN1] WARNING: Deffunction <name> only partially deleted due to usage by other constructs.
During a clear or deletion of all deffunctions, only the actions of a deffunction were deleted because another construct which also could not be deleted referenced the deffunction.
Example:
CLIPS>
(deffunction foo ()
(printout t “Hi there!” crlf))
CLIPS>
(deffunction bar ()
(foo)
(undeffunction *))
CLIPS> (bar)
[GENRCBIN1] WARNING: COOL not installed! User-defined class in method restriction substituted with OBJECT.
This warning occurs when a generic function method restricted by defclasses is loaded using the bload command into a CLIPS configuration where the object language is not enabled. The restriction containing the defclass will match any of the primitive types.
[OBJBIN1] WARNING: Around message-handlers are not supported in this environment.
This warning occurs when an around message-handler is loaded using the bload command into a CLIPS configuration not supporting imperative message-handlers.
[OBJBIN2] WARNING: Before and after message-handlers are not supported in this environment.
This warning occurs when a before or an after message-handler is loaded using the bload command into a CLIPS configuration not supporting auxiliary message-handlers.
Appendix F: CLIPS Error Messages ====================
CLIPS typically will display two kinds of error messages: those associated with executing constructs and those associated with loading constructs. This appendix describes some of the more common error messages and what they mean. Each message begins with a unique identifier enclosed in brackets; the messages are listed here in alphabetic order according to the identifier.
[AGENDA1] Salience value must be an integer value.
Salience requires a integer argument and will otherwise result in this error message.
Example:
CLIPS> (defrule error (declare (salience a)) =>)
[AGENDA2] Salience value out of range <min> to <max>
The range of allowed salience has an explicit limit; this error message will result if the value is out of that range.
Example:
CLIPS> (defrule error (declare (salience 20000)) =>)
[AGENDA3] This error occurred while evaluating the salience [for rule <name>]
When an error results from evaluating a salience value for a rule, this error message is given.
[ANALYSIS1] Duplicate pattern-address <variable name> found in CE <CE number>.
This message occurs when two facts or instances are bound to the same pattern-address variable.
Example:
CLIPS> (defrule error ?f <- (a) ?f <- (b) =>)
[ANALYSIS2] Pattern-address <variable name> used in CE #2 was previously bound within a pattern CE.
A variable first bound within a pattern cannot be later bound to a fact-address.
Example:
CLIPS> (defrule error (a ?f) ?f <- (b) =>)
[ANALYSIS3] Variable <variable name> is used as both a single and multifield variable.
Variables on the LHS of a rule cannot be bound to both single and multifield variables.
Example:
CLIPS> (defrule error (a ?x $?x) =>)
[ANALYSIS4] Variable <variable name> [found in the expression <expression>]
was referenced in CE <CE number> <field or slot identifier> before being defined
A variable cannot be referenced before it is defined and, thus, results in this error message.
Example:
CLIPS> (defrule foo (a ~?x) =>)
[ARGACCES1] Function <name> expected at least <minimum> and no more than <maximum> argument(s)
This error occurs when a function receives less than the minimum number or more than the maximum number of argu?ment(s) expected.
[ARGACCES2] Function <function-name> was unable to open file <file-name>
This error occurs when the specified function cannot open a file.
[ARGACCES3] Function <name1> received a request from function <name2> for argument #<number> which is non-existent
This error occurs when a function is passed fewer arguments than were expected.
[ARGACCES4] Function <name> expected exactly <number> argument(s)
This error occurs when a function that expects a precise number of argument(s) re?ceives an incorrect number of arguments.
[ARGACCES4] Function <name> expected at least <number> argument(s)
This error occurs when a function does not receive the minimum number of argu?ment(s) that it expected.
[ARGACCES4] Function <name> expected no more than <number> argument(s)
This error occurs when a function receives more than the maximum number of argu?ment(s) expected.
[ARGACCES5] Function <name> expected argument #<number> to be of type <data-type>
This error occurs when a function is passed the wrong type of argument.
[ARGACCES6] Function <name1> received a request from function <name2> for argument #<number> which is not of type <data-type>
This error occurs when a function requests from another function the wrong type of ar?gument, typically a string or symbol, when expecting a number or vice versa.
[BLOAD1] Cannot load <construct type> construct with binary load in effect.
If the bload command was used to load in a binary image, then the named construct cannot be entered until a clear command has been performed to remove the binary image.
[BLOAD2] File <file-name> is not a binary construct file
This error occurs when the bload command is used to load a file that was not cre?ated with the bsave command.
[BLOAD3] File <file-name> is an incompatible binary construct file
This error occurs when the bload command is used to load a file that was cre?ated with the bsave command using a different version of CLIPS.
[BLOAD4] The CLIPS environment could not be cleared.
Binary load cannot continue.
A binary load cannot be performed unless the current CLIPS environment can be cleared.
Binary <operation> cannot continue.
This error occurs when the current binary image cannot be cleared because some constructs are still being used. The <operation> in progress may either be a binary load or a binary clear.
This error occurs when a binary image is loaded that calls functions which were available in the CLIPS executable that originally created the binary image, but which are not available in the CLIPS executable that is loading the binary image.
[BSAVE1] Cannot perform a binary save while a binary load is in effect.
The bsave command does not work when a binary image is loaded.
[CLASSEXM1] Inherited slot <slot-name> from class <slot-name> is not valid for function slot-publicp
This error message occurs when the function slot-publicp is given an inherited slot. This function can only be used on slots defined in the given class.
Example:
CLIPS>
(defclass FOO (is-a USER)
(slot woz (visibility private)))
CLIPS>
(defclass BAR (is-a FOO))
CLIPS> (slot-publicp BAR woz)
[CLASSFUN1] Unable to find class <class name> in function <function name>.
This error message occurs when a function is given a non-existent class name.
Example:
CLIPS> (class-slots FOO)
[CLASSFUN2] Maximum number of simultaneous class hierarchy traversals exceeded <number>.
This error is usually caused by too many simultaneously active instance-set queries, e.g., do-for-all-instances. The direct or indirect nesting of instance-set query functions is limited in the following way:
Ci is the number of members in an instance-set for the ith nested instance-set query function.
N is the number of nested instance-set query functions.
| <= 128 (the default upper limit) |
Example:
CLIPS>
(deffunction my-func ()
(do-for-instance ((?a USER) (?b USER) (?c USER)) TRUE
(printout t ?a ” ” ?b ” ” ?c crlf))
; The sum here is C1 = 3 which is OK.
CLIPS>
(do-for-all-instances ((?a OBJECT) (?b OBJECT)) TRUE
(my-func))
; The sum here is C1 + C2 = 2 + 3 = 5 which is OK.
The default upper limit of 128 should be sufficient for most if not all applications. However, the limit may be increased by editing the header file OBJECT.H and recompiling CLIPS.
[CLASSPSR1] An abstract class cannot be reactive.
Only concrete classes can be reactive.
Example:
CLIPS>
(defclass FOO (is-a USER)
(role abstract)
(pattern-match reactive))
[CLASSPSR2] Cannot redefine a predefined system class.
Predefined system classes cannot be modified by the user.
Example:
CLIPS> (defclass STRING (is-a NUMBER))
[CLASSPSR3] <name> class cannot be redefined while outstanding references to it still exist.
This error occurs when an attempt to redefine a class is made under one or both of the following two circumstances:
- The class (or any of its subclasses) has instances.
2) The class (or any of its subclasses) appear in the parameter restrictions of any generic function method.
Before the class can be redefined, all such instances and methods must be deleted.
Example:
CLIPS> (defclass A (is-a USER))
CLIPS> (defmethod foo ((?a A LEXEME)))
CLIPS> (defclass A (is-a OBJECT)))
[CLASSPSR4] Class <attribute> already declared.
Only one specification of a class attribute is allowed.
Example:
CLIPS>
(defclass A (is-a USER)
(role abstract)
(role concrete))
[CLSLTPSR1] Duplicate slots not allowed.
Slots in a defclass must be unique.
Example:
CLIPS>
(defclass A (is-a USER)
(slot foo)
(slot foo))
[CLSLTPSR2] <name> facet already specified.
Only one occurrence of a facet per slot is allowed.
Example:
CLIPS>
(defclass A (is-a USER)
(slot foo (access read-only)
(access read-write)))
[CLSLTPSR3] Cardinality facet can only be used with multifield slots
Single-field slots by definition have a cardinality of one.
Example:
CLIPS>
(defclass A (is-a USER)
(slot foo (cardinality 3 5)))
[CLSLTPSR4] read-only slots must have a default value
Since slots cannot be unbound and read-only slots cannot be set after initial creation of the instance, read-only slots must have a default value.
Example:
CLIPS>
(defclass A (is-a USER)
(slot foo (access read-only)
(default ?NONE)))
[CLSLTPSR5] read-only slots cannot have a write accessor
Since read-only slots cannot be changed after initializationof the instance, a write accessor (put- message-handler) is not allowed.
Example:
CLIPS>
(defclass A (is-a USER)
(slot foo (access read-only)
(create-accessor write)))
[CLSLTPSR6] no-inherit slots cannot also be public
no-inherit slots are by definition not accessible to subclasses and thus only visible to the parent class.
Example:
CLIPS>
(defclass A (is-a USER)
(slot foo (propagation no-inherit)
(visibility public)))
[COMMLINE1] Expected a ‘(‘, constant, or global variable
This message occurs when a top-level command does not begin with a ‘(‘, constant, or global variable.
Example:
CLIPS> )
[COMMLINE2] Expected a command.
This message occurs when a top-level command is not a symbol.
Example:
CLIPS> (“facts”
[CONSCOMP1] Invalid file name <fileName> contains ‘.’
A ‘.’ cannot be used in the file name prefix that is passed to the constructs-to-c command since this prefix is used to generate file names and some operating systems do not allow more than one ‘.’ to appear in a file name.
[CONSTRCT1] Some constructs are still in use. Clear cannot continue.
This error occurs when the clear command is issued when a construct is in use (such as a rule that is firing).
[CSTRCPSR1] Expected the beginning of a construct.
This error occurs when the load command expects a left parenthesis followed a construct type and these token types are not found.
[CSTRCPSR2] Missing name for <construct-type> construct
This error occurs when the name is missing for a construct that requires a name.
Example:
CLIPS> (defgeneric ())
[CSTRCPSR3] Cannot define <construct-type> <construct-name> because of an import/export conflict.
or
[CSTRCPSR3] Cannot define defmodule <defmodule-name> because of an import/export conflict cause by the <construct-type> <construct-name>.
A construct cannot be defined if defining the construct would allow two different definitions of the same construct type and name to both be visible to any module.
Example:
CLIPS> (defmodule MAIN (export ?ALL))
CLIPS> (deftemplate MAIN::foo)
CLIPS> (defmodule BAR (import MAIN ?ALL))
CLIPS> (deftemplate BAR::foo (slot x))
[CSTRCPSR4] Cannot redefine <construct-type> <construct-name> while it is in use.
A construct cannot be redefined while it is being used by another construct or other data structure (such as a fact or instance).
Example:
CLIPS> (clear)
CLIPS> (deftemplate bar)
CLIPS> (assert (bar))
<Fact-0>
CLIPS> (deftemplate (bar (slot x)))
[CSTRNCHK1] Message Varies
This error ID covers a range of messages indicating a type, value, range, or cardinality violation.
Example:
CLIPS> (deftemplate foo (slot x (type SYMBOL)))
CLIPS> (assert (foo (x 3)))
[CSTRNPSR1] The <first attribute name> attribute conflicts with the <second attribute name> attribute.
This error message occurs when two slot attributes conflict.
Example:
CLIPS> (deftemplate foo (slot x (type SYMBOL) (range 0 2)))
[CSTRNPSR2] Minimum <attribute> value must be less than
or equal to the maximum <attribute> value.
The minimum attribute value for the range and cardinality attributes must be less than or equal to the maximum attribute value for the attribute.
Example:
CLIPS> (deftemplate foo (slot x (range 8 1)))
[CSTRNPSR3] The <first attribute name> attribute cannot be used in conjunction with the <second attribute name> attribute.
The use of some slot attributes excludes the use of other slot attributes.
Example:
CLIPS> (deftemplate foo (slot x (allowed-values a)
(allowed-symbols b)))
[CSTRNPSR4] Value does not match the expected type for the <attribute name> attribute.
The arguments to an attribute must match the type expected for that attribute (e.g. integers must be used for the allowed-integers attribute).
Example:
CLIPS> (deftemplate example (slot x (allowed-integers 3.0)))
[CSTRNPSR5] The cardinality attribute can only be used with multifield slots.
The cardinality attribute can only be used for slots defined with the multislot keyword.
Example:
CLIPS> (deftemplate foo (slot x (cardinality 1 1)))
[CSTRNPSR6] Minimum cardinality value must be greater than or equal to zero.
A multislot with no value has a cardinality of 0. It is not possible to have a lower cardinality.
Example:
CLIPS> (deftemplate foo (multislot x (cardinality -3 1)))
[DEFAULT1] The default value for a single field slot must be a single field value.
This error occurs when the default or default-dynamic attribute for a single-field slot does not contain a single value or an expression returning a single value.
Example:
CLIPS> (deftemplate error (slot x (default)))
[DFFNXPSR1] Deffunctions are not allowed to replace constructs.
A deffunction cannot have the same name as any construct.
Example:
CLIPS> (deffunction defgeneric ())
[DFFNXPSR2] Deffunctions are not allowed to replace external functions.
A deffunction cannot have the same name as any system or user-defined external function.
Example:
CLIPS> (deffunction + ())
[DFFNXPSR3] Deffunctions are not allowed to replace generic functions.
A deffunction cannot have the same name as any generic function.
Example:
CLIPS> (defgeneric foo)
CLIPS> (deffunction foo ())
[DFFNXPSR4] Deffunction <name> may not be redefined while it is executing.
A deffunction can be loaded at any time except when a deffunction of the same name is already executing.
Example:
CLIPS>
(deffunction foo ()
(build “(deffunction foo ())”))
CLIPS> (foo)
[DFFNXPSR5] Defgeneric <name> imported from module <module name> conflicts with this deffunction.
A deffunction cannot have the same name as any generic function imported from another module.
Example:
CLIPS> (defmodule MAIN (export ?ALL))
CLIPS> (defmethod foo ())
CLIPS> (defmodule FOO (import MAIN ?ALL))
CLIPS> (deffunction foo)
[DRIVE1] This error occurred in the join network
Problem resides in join #<pattern-number> in rule(s):
<problem-rules>+
This error pinpoints other evaluation errors associated with evaluating an expression within the join network. The specific pattern of the problem rules is identified.
[EMATHFUN1] Domain error for <function-name> function
This error occurs when an argument passed to a math function is not in the domain of values for which a return value exists.
[EMATHFUN2] Argument overflow for <function-name> function
This error occurs when an argument to an extended math function would cause a numeric overflow.
[EMATHFUN3] Singularity at asymptote in <function-name> function
This error occurs when an argument to a trigonometric math function would cause a singularity.
[EVALUATN1] Variable <name> is unbound
This error occurs when a local variable not set by a previous call to bind is accessed at the top level.
Example:
CLIPS> (progn ?error)
[EVALUATN2] No function, generic function or deffunction of name <name> exists for external call.
IThis error occurs only when an invalid function name is passed to the external C access routine CLIPSFunctionCall.
[EXPRNPSR1] A function name must be a symbol
In the following example, ‘~’ is recognized by CLIPS as an operator, not a function:
Example:
CLIPS> (+ (~ 3 4) 4)
[EXPRNPSR2] Expected a constant, variable, or expression
In the following example, ‘~’ is an operator and is illegal as an argument to a function call:
Example:
CLIPS> (<= ~ 4)
[EXPRNPSR3] Missing function declaration for <name>
CLIPS does not recognize <name> as a declared function and gives this error message.
Example:
CLIPS> (xyz)
[EXPRNPSR4] $ Sequence operator not a valid argument for <name>.
The sequence expansion operator cannot be used with certain functions.
Example:
CLIPS> (set-sequence-operator-recognition TRUE)
FALSE
CLIPS> (defrule foo (x $?y) => (assert (x1 $?y)))
[FACTMCH1] This error occurred in the pattern network
Currently active fact: <newly assert fact>
Problem resides in slot <slot name>
Of pattern #<pattern-number> in rule(s):
<problem-rules>+
This error pinpoints other evaluation errors associated with evaluating an expression within the pattern network. The specific pattern and field of the problem rules are identified.
[FACTMNGR1] Facts may not be retracted during pattern-matching
or
[FACTMNGR2] Facts may not be retracted during pattern-matching
Functions used on the LHS of a rule should not have side effects (such as the creation of a new instance or fact).
Example:
CLIPS>
(defrule error
(test (assert (blah)))
=>)
CLIPS> (reset)
[FACTRHS1] Template <name> does not exist for assert.
This error occurs when an assert is attempted for a deftemplate which does not exist in a runtime or active bload image. In other situations, CLIPS will create an implied deftemplate if one does not already exist.
Example:
CLIPS> (clear)
CLIPS> (bsave error.bin)
TRUE
CLIPS> (bload error.bin)
TRUE
CLIPS> (assert (error))
[GENRCCOM1] No such generic function <name> in function undefmethod.
This error occurs when the generic function name passed to the undefmethod function does not exist.
Example:
CLIPS> (clear)
CLIPS> (undefmethod yak 3)
[GENRCCOM2] Expected a valid method index in function undefmethod.
This error occurs when an invalid method index is passed to undefmethod (e.g. a negative integer or a symbol other than *).
Example:
CLIPS> (defmethod foo ())
CLIPS> (undefmethod foo a))
[GENRCCOM3] Incomplete method specification for deletion.
It is illegal to specify a non-wildcard method index when a wildcard is given for the generic function in the function undefmethod.
Example:
CLIPS> (undefmethod * 1)
[GENRCCOM4] Cannot remove implicit system function method for generic function <name>.
A method corresponding to a system defined function cannot be deleted.
Example:
CLIPS> (defmethod integer ((?x SYMBOL)) 0)
CLIPS> (list-defmethods integer)
integer #SYS1 (NUMBER)
integer #2 (SYMBOL)
For a total of 2 methods.
CLIPS> (undefmethod integer 1)
[GENRCEXE1] No applicable methods for <name>.
The generic function call arguments do not satisfy any method?s parameter restrictions.
Example:
CLIPS> (defmethod foo ())
CLIPS> (foo 1 2)
[GENRCEXE2] Shadowed methods not applicable in current context.
No shadowed method is available when the function call-next-method is called.
Example:
CLIPS> (call-next-method)
[GENRCEXE3] Unable to determine class of <value> in generic function <name>.
The class or type of a generic function argument could not be determined for comparison to a method type restriction.
Example:
CLIPS> (defmethod foo ((?a INTEGER)))
CLIPS> (foo [bogus-instance])
[GENRCEXE4] Generic function <name> method #<index> is not applicable to the given arguments.
This error occurs when call-specific-method is called with an inappropriate set of arguments for the specified method.
Example:
CLIPS> (defmethod foo ())
CLIPS> (call-specific-method foo 1 abc)
[GENRCFUN1] Defgeneric <name> cannot be modified while one of its methods is executing.
Defgenerics can?t be redefined while one of their methods is currently executing.
Example:
CLIPS> (defgeneric foo)
CLIPS> (defmethod foo () (build “(defgeneric foo)”))
CLIPS> (foo)
[GENRCFUN2] Unable to find method <name> #<index> in function <name>.
No generic function method of the specified index could be found by the named function.
Example:
CLIPS> (defmethod foo 1 ())
CLIPS> (ppdefmethod foo 2)
[GENRCFUN3] Unable to find generic function <name> in function <name>.
No generic function method of the specified index could be found by the named function.
Example:
CLIPS> (preview-generic balh)
[GENRCPSR1] Expected ‘)’ to complete defgeneric.
A right parenthesis completes the definition of a generic function header.
Example:
CLIPS> (defgeneric foo ())
[GENRCPSR2] New method #<index1> would be indistinguishable from method #<index2>.
An explicit index has been specified for a new method that does not match that of an older method which has identical parameter restrictions.
Example:
CLIPS> (defmethod foo 1 ((?a INTEGER)))
CLIPS> (defmethod foo 2 ((?a INTEGER)))
[GENRCPSR3] Defgenerics are not allowed to replace constructs.
A generic function cannot have the same name as any construct.
[GENRCPSR4] Deffunction <name> imported from module <module name> conflicts with this defgeneric.
A deffunction cannot have the same name as any generic function imported from another module.
Example:
CLIPS> (defmodule MAIN (export ?ALL))
CLIPS> (deffunction foo ())
CLIPS> (defmodule FOO (import MAIN ?ALL))
CLIPS> (defmethod foo)
[GENRCPSR5] Generic functions are not allowed to replace deffunctions.
A generic function cannot have the same name as any deffunction.
[GENRCPSR6] Method index out of range.
A method index cannot be greater than the maximum value of an integer or less than 1.
Example:
CLIPS> (defmethod foo 0 ())
[GENRCPSR7] Expected a ‘(‘ to begin method parameter restrictions.
A left parenthesis must begin a parameter restriction list for a method.
Example:
CLIPS> (defmethod foo)
[GENRCPSR8] Expected a variable for parameter specification.
A method parameter with restrictions must be a variable.
Example:
CLIPS> (defmethod foo ((abc)))
[GENRCPSR9] Expected a variable or ‘(‘ for parameter specification.
A method parameter must be a variable with or without restrictions.
Example:
CLIPS> (defmethod foo (abc))
[GENRCPSR10] Query must be last in parameter restriction.
A query parameter restriction must follow a type parameter restriction (if any).
Example:
CLIPS> (defmethod foo ((?a (< ?a 1) INTEGER)))
[GENRCPSR11] Duplicate classes/types not allowed in parameter restriction.
A method type parameter restriction may have only a single occurrence of a particular class.
Example:
CLIPS> (defmethod foo ((?a INTEGER INTEGER)))
[GENRCPSR12] Binds are not allowed in query expressions.
Binding new variables in a method query parameter restriction is illegal.
Example:
CLIPS> (defmethod foo ((?a (bind ?b 1))))
[GENRCPSR13] Expected a valid class/type name or query.
Method parameter restrictions consist of zero or more class names and an optional query expression.
Example:
CLIPS> (defmethod foo ((?a 34)))
[GENRCPSR14] Unknown class/type in method.
Classes in method type parameter restrictions must already be defined.
Example:
CLIPS> (defmethod foo ((?a bogus-class)))
[GENRCPSR15] <name> class is redundant.
All classes in a method type parameter restriction should be unrelated.
Example:
CLIPS> (defmethod foo ((?a INTEGER NUMBER)))
[GENRCPSR16] The system function <name> cannot be overloaded.
Some system functions canot be overloaded.
Example:
CLIPS> (defmethod if ())
[GENRCPSR17] Cannot replace the implicit system method #<integer>.
A system function can not be overloaded with a method that has the exact number and types of arguments.
Example:
CLIPS> (defmethod integer ((?x NUMBER)) (* 2 ?x))
[GLOBLDEF1] Global variable <variable name> is unbound.
A global variable must be defined before it can be accessed at the command prompt or elsewhere.
Example:
CLIPS> (clear)
CLIPS> ?*x*
[GLOBLPSR1] Global variable <variable name> was referenced, but is not defined.
A global variable must be defined before it can be accessed at the command prompt or elsewhere.
Example:
CLIPS> (clear)
CLIPS> ?*x*
[INCRRSET1] The incremental reset behavior cannot be changed with rules loaded.
The incremental reset behaviour can only be changed when there are no currently defined rules.
[INHERPSR1] A class may not have itself as a superclass.
A class may not inherit from itself.
Example:
CLIPS> (defclass A (is-a A))
[INHERPSR2] A class may inherit from a superclass only once.
All direct superclasses of a class must be unique.
Example:
CLIPS> (defclass A (is-a USER USER))
[INHERPSR3] A class must be defined after all its superclasses.
Subclasses must be defined last.
Example:
CLIPS> (defclass B (is-a A))
[INHERPSR4] Must have at least one superclass.
All user-defined classes must have at least one direct superclass.
Example:
CLIPS> (defclass A (is-a))
[INHERPSR5] Partial precedence list formed: <classa> <classb> ?E<classc>
Precedence loop in superclasses: <class1> <class2> ?E<classn> <class1>
No class precedence list satisfies the rules specified in section 9.3.1.1 for the given direct superclass list. The message shows a conflict for <class1> because the precedence implies that <class1> must both precede and succeed <class2> through <classn>. The full loop can be used to help identify which particular classes are causing the problem. This loop is not necessarily the only loop in the precedence list; it is the first one detected. The part of the precedence list which was successfully formed is also listed.
Example:
CLIPS> (defclass A (is-a MULTIFIELD FLOAT SYMBOL))
CLIPS> (defclass B (is-a SYMBOL FLOAT))
CLIPS> (defclass C (is-a A B))
[INHERPSR6] A user-defined class cannot be a subclass of <name>.
The INSTANCE, INSTANCE-NAME, and INSTANCE-ADDRESS classes cannot have any subclasses.
Example:
CLIPS> (defclass A (is-a INSTANCE))
[INSCOM1] Undefined type in function <name>.
The evaluation of an expression yielded something other than a recognized class or primitive type.
[INSFILE1] Function <function-name> could not completely process file <name>.
This error occurs when an instance definition is improperly formed in the input file for the load-instances, restore-instances, or bload-instances command.
Example:
CLIPS> (load-instances bogus.txt)
[INSFILE2] <file-name> file is not a binary instances file.
or
[INSFILE3] <file-name> file is not a compatible binary instances file.
This error occurs when bload-instances attempts to load a file that was not created with bsave-instances or when the file being loaded was created by a different version of CLIPS.
Example:
CLIPS> (reset)
CLIPS> (save-instances foo.ins)
1
CLIPS> (bload-instances foo.ins)
[INSFILE4] Function bload-instances unable to load instance <instance-name>.
This error occurs when an instance specification in the input file for the bload-instances command could not be created.
Example:
CLIPS> (defclass A (is-a USER) (role concrete))
CLIPS> (make-instance of A)
[gen1]
CLIPS> (bsave-instances foo.bin)
1
CLIPS> (clear)
CLIPS> (defclass A (is-a USER))
CLIPS> (bload-instances foo.bin)
[INSFUN1] Expected a valid instance in function <name>.
The named function expected an instance-name or address as an argument.
Example:
CLIPS> (initialize-instance 34)
[INSFUN2] No such instance <name> in function <name>.
This error occurs when the named function cannot find the specified instance.
Example:
CLIPS> (instance-address [bogus-instance])
[INSFUN3] No such slot <name> in function <name>.
This error occurs when the named function cannot find the specified slot in an instance or class.
Example:
CLIPS> (defclass A (is-a USER))
CLIPS> (slot-writablep A b)
[INSFUN4] Invalid instance-address in function <name>.
This error occurs when an attempt is made to use the address of a deleted instance.
Example:
CLIPS> (defclass A (is-a USER))
CLIPS> (make-instance a of A)
[a]
CLIPS> (defglobal ?*x* = (instance-address a))
CLIPS> (make-instance a of A)
[a]
CLIPS> (class ?*x*)
[INSFUN5] Cannot modify reactive instance slots while pattern-matching is in process.
CLIPS does not allow reactive instance slots to be changed while pattern-matching is taking place. Functions used on the LHS of a rule should not have side effects (such as the changing slot values).
Example:
CLIPS>
(defclass FOO (is-a USER)
(role concrete)
(pattern-match reactive)
(slot x (create-accessor read-write)))
CLIPS> (make-instance x of FOO)
[x]
CLIPS> (defrule BAR (x) (test (send [x] put-x 3)) =>)
CLIPS> (assert (x))
[INSFUN6] Unable to pattern-match on shared slot <name> in class <name>.
This error occurs when the number of simultaneous class hierarchy traversals is exceeded while pattern-matching on a shared slot. See the related error message [CLASSFUN2] for more details.
[INSFUN7] <multifield-value> illegal for single-field slot <name> of instance <name> found in <function-call or message-handler>.
Single-field slots in an instance can hold only one atomic value.
Example:
CLIPS> (set-static-constraint-checking FALSE)
TRUE
CLIPS>
(defclass FOO (is-a USER)
(role concrete)
(slot foo))
CLIPS>
(defmessage-handler FOO error ()
(bind ?self:foo 1 2 3))
CLIPS> (make-instance foo of FOO)
[foo]
CLIPS> (send [foo] error)
[INSFUN8] Void function illegal value for slot <name> of instance <name> found in <function-call or message-handler>.
Only functions which have a return value can be used to generate values for an instance slot.
Example:
CLIPS> (set-static-constraint-checking FALSE)
TRUE
CLIPS>
(defclass FOO (is-a USER)
(role concrete)
(slot foo))
CLIPS>
(defmessage-handler FOO error ()
(bind ?self:foo (instances)))
CLIPS> (make-instance foo of FOO)
[foo]
CLIPS> (send [foo] error)
[INSMNGR1] Expected a valid name for new instance.
make-instance expects a symbol or an instance-name for the name of a new instance.
Example:
CLIPS> (make-instance 34 of A)
[INSMNGR2] Expected a valid class name for new instance.
make-instance expects a symbol for the class of a new instance.
Example:
CLIPS> (make-instance a of 34)
[INSMNGR3] Cannot create instances of abstract class <name>.
Direct instances of abstract classes, such as the predefined system classes, are illegal.
Example:
CLIPS> (make-instance [foo] of USER)
[INSMGNR4] The instance <name> has a slot-value which depends on the instance definition.
The initialization of an instance is recursive in that a slot-override or default-value tries to create or reinitialize the same instance.
Example:
CLIPS>
(defclass A (is-a USER)
(slot foo))
CLIPS>
(make-instance a of A (foo (make-instance a of A)))
[INSMNGR5] Unable to delete old instance <name>.
make-instance will attempt to delete an old instance of the same name if it exists. This error occurs if that deletion fails.
Example:
CLIPS> (defclass A (is-a USER))
CLIPS>
(defmessage-handler A delete around ()
(if (neq (instance-name ?self) [a]) then
(call-next-handler)))
CLIPS> (make-instance a of A)
CLIPS> (make-instance a of A)
[INSMNGR6] Cannot delete instance <name> during initialization.
The evaluation of a slot-override in make-instance or initialize-instance attempted to delete the instance.
Example:
CLIPS>
(defclass A (is-a USER)
(slot foo))
CLIPS>
(defmessage-handler A put-foo after ($?any)
(delete-instance))
CLIPS> (make-instance a of A (foo 2))
[INSMNGR7] Instance <name> is already being initialized.
An instance cannot be reinitialized during initialization.
Example:
CLIPS> (defclass A (is-a USER))
CLIPS> (make-instance a of A)
CLIPS>
(defmessage-handler A init after ()
(initialize-instance ?self))
CLIPS> (initialize-instance a)
CLIPS> (send [a] try)
[INSMNGR8] An error occurred during the initialization of instance <name>.
This message is displayed when an evaluation error occurs while the init message is executing for an instance.
[INSMNGR9] Expected a valid slot name for slot-override.
make-instance and initialize-instance expect symbols for slot names.
Example:
CLIPS> (defclass A (is-a USER))
CLIPS> (make-instance a of A (34 override-value))
[INSMNGR10] Cannot create instances of reactive classes while pattern-matching is in process.
CLIPS does not allow instances of reactive classes to be created while pattern-matching is taking place. Functions used on the LHS of a rule should not have side effects (such as the creation of a new instance or fact).
Example:
CLIPS> (defclass FOO (is-a USER) (role concrete) (pattern-match reactive))
CLIPS> (defrule BAR (x) (test (make-instance of FOO)) =>)
CLIPS> (assert (x))
[INSMNGR11] Invalid module specifier in new instance name.
This error occurs when the module specifier in the instance-name is illegal (such as an undefined module name).
Example:
CLIPS> (defclass FOO (is-a USER) (role concrete))
CLIPS> (make-instance BOGUS::x of FOO)
[INSMNGR12] Cannot delete instances of reactive classes while pattern-matching is in process.
CLIPS does not allow instances of reactive classes to be deleted while pattern-matching is taking place. Functions used on the LHS of a rule should not have side effects (such as the deletion of a new instance or the retraction of a fact).
Example:
CLIPS> (defclass FOO (is-a USER) (role concrete) (pattern-match reactive))
CLIPS> (make-instance x of FOO)
[x]
CLIPS> (defrule BAR (x) (test (send [x] delete)) =>)
CLIPS> (assert (x))
[INSMNGR13] Slot <slot-name> does not exist in instance <instance-name>.
This error occurs when the slot name of a slot override does not correspond to any of the valid slot names for an instance.
Example:
CLIPS> (defclass FOO (is-a USER) (role concrete))
CLIPS> (make-instance of FOO (x 3))
[INSMNGR14] Override required for slot <slot-name> in instance <instance-name>.
If the ?NONE keyword was specified with the default attribute for a slot, then a slot override must be provided when an instance containing that slot is created.
Example:
CLIPS> (defclass FOO (is-a USER)
(role concrete)
(slot x (default ?NONE)))
CLIPS> (make-instance of FOO)
[INSMNGR15] init-slots not valid in this context.
The special function init-slots (for initializing slots of an instance to the class default values) can only be called during the dispatch of an init message for an instance, i.e., in an init message-handler.
Example:
CLIPS>
(defmessage-handler INITIAL-OBJECT error ()
(init-slots))
CLIPS> (reset)
CLIPS> (send [initial-object] error)
[INSMODDP1] Direct/message-modify message valid only in modify-instance.
The direct-modify and message-modify message-handlers attached to the class USER can only be called as a result of the appropriate message being sent.by the modify-instance or message-modify-instance functions. Additional handlers may be defined, but the message can only be sent in this context.
Example:
CLIPS> (reset)
CLIPS> (send [initial-object] direct-modify 0)
[INSMODDP2] Direct/message-duplicate message valid only in duplicate-instance.
The direct-duplicate and message-duplicate message-handlers attached to the class USER can only be called as a result of the appropriate message being sent.by the duplicate-instance or message-duplicate-instance functions. Additional handlers may be defined, but the message can only be sent in this context.
Example:
CLIPS> (reset)
CLIPS> (send [initial-object] direct-duplicate 0 0)
[INSMODDP3] Instance copy must have a different name in duplicate-instance.
If an instance-name is specified for the new instance in the call to duplicate-instance, it must be different from the source instance?s name.
Example:
CLIPS> (reset)
CLIPS> (duplicate-instance initial-object to initial-object)
[INSMULT1] Function <name> cannot be used on single-field slot <name> in instance <name>.
The functions described in section 12.13.4.12, such as slot-insert$, can only operate on multifield slots.
Example:
CLIPS>
(defclass A (is-a USER)
(slot foo))
CLIPS> (make-instance a of A)
[a]
CLIPS> (slot-insert$ a foo 1 abc def)
[INSQYPSR1] Duplicate instance-set member variable name in function <name>.
Instance-set member variables in an instance-set query function must be unique.
Example:
CLIPS> (any-instancep ((?a OBJECT) (?a OBJECT)) TRUE)
[INSQYPSR2] Binds are not allowed in instance-set query in function <name>.
An instance-set query cannot bind variables.
Example:
CLIPS>
(any-instancep ((?a OBJECT) (?b OBJECT))
(bind ?c 1))
[INSQYPSR3] Cannot rebind instance-set member variable <name> in function <name>.
Instance-set member variables cannot be changed within the actions of an instance-set query function.
Example:
CLIPS>
(do-for-all-instances ((?a USER))
(if (slot-existp ?a age) then
(> ?a:age 30))
(bind ?a (send ?a get-brother)))
[IOFUN1] Illegal logical name used for <function name> function.
A logical name must be either a symbol, string, instance-name, float, or integer.
Example:
(printout (create$ a b c) x)
[IOFUN2] Logical name <logical name> already in use.
A logical name cannot be associated with two different files.
Example:
CLIPS> (open “foo.txt” foo “w”)
TRUE
CLIPS> (open “foo2.txt” foo “w”)
[MEMORY1] Out of memory
This error indicates insufficient memory exists to expand internal struc?tures enough to allow continued operation (causing an exit to the operating system).
[MEMORY2] Release error in genfree
This error indicates a problem in the memory management routines.
[MEMORY3] Unable to allocate memory block > 32K
This error occurs when the bload function attempts to allocate a block of memory larger than 32K and the operating system does not permit blocks greater than 32K to be allocated. This will only occur on machines which have 2 byte integers (excluding the Macintosh and IBM PC which have machine dependent code provided so that they can allocate more than 32K). When this error occurs, CLIPS exits to the operating system.
[MISCFUN1] expand$ must be used in the argument list of a function call.
The expand$ function may not be called unless it is within the argument list of another function.
Example:
CLIPS> (expand$ (create$ a b c))
[MODULDEF1] Illegal use of the module specifier.
The module specifier can only be used as part of a defined construct?s name or as an argument to a function.
Example:
CLIPS> (deffunction y ())
CLIPS> (MAIN::y)
[MODULPSR1] Module <module name> does not export any constructs.
or
[MODULPSR1] Module <module name> does not export any <construct type> constructs.
or
[MODULPSR1] Module <module name> does not export the <construct type> <construct name>.
A construct cannot be imported from a module unless the defmodule exports that construct.
Example:
CLIPS> (clear)
CLIPS> (defmodule BAR)
CLIPS> (deftemplate BAR::bar)
CLIPS> (defmodule FOO (import BAR deftemplate bar)))
[MSGCOM1] Incomplete message-handler specification for deletion.
It is illegal to specify a non-wildcard handler index when a wildcard is given for the class in the external C function UndefmessageHandler(). This error can only be generated when a user-defined external function linked with CLIPS calls this function incorrectly.
[MSGCOM2] Unable to find message-handler <name> <type> for class <name> in function <name>.
This error occurs when the named function cannot find the specified message-handler.
Example:
CLIPS> (ppdefmessage-handler USER foo around)
[MSGCOM3] Unable to delete message-handlers.
This error occurs when a message-handler can?t be deleted (such as when a binary image is loaded).
Example:
CLIPS> (defclass FOO (is-a USER) (role concrete))
CLIPS> (defmessage-handler FOO bar ())
CLIPS> (bsave foo.bin)
TRUE
CLIPS> (bload foo.bin)
TRUE
CLIPS> (undefmessage-handler FOO bar)
[MSGFUN1] No applicable primary message-handlers found for <message>.
No primary message-handler attached to the object?s classes matched the name of the message.
Example:
CLIPS> (defclass A (is-a USER))
CLIPS> (make-instance a of A)
[a]
CLIPS> (send [a] bogus-message)
[MSGFUN2] Message-handler <name> <type> in class <name> expected exactly/at least <number> argument(s).
The number of message arguments was inappropriate for one of the applicable message-handlers.
Example:
CLIPS> (defclass A (is-a USER))
CLIPS> (defmessage-handler USER foo (?a ?b))
CLIPS> (make-instance a of A)
[a]
CLIPS> (send [a] foo)
[MSGFUN3] <name> slot in instance <name>: write access denied.
This error occurs when an attempt is made to change the value of a read-only slot.
Example:
CLIPS>
(defclass A (is-a USER)
(slot foo (default 100)
(read-only)))
CLIPS> (make-instance a of A)
[a]
CLIPS> (send [a] put-foo)
[MSGFUN4] <function> may only be called from within message-handlers.
The named function operates on the active instance of a message and thus can only be called by message-handlers.
Example:
CLIPS> (ppinstance)
[MSGFUN5] <function> operates only on instances.
The named function operates on the active instance of a message and can only handle instances of user-defined classes (not primitive type objects).
Example:
CLIPS>
(defmessage-handler INTEGER print ()
(ppinstance))
CLIPS> (send 34 print)
[MSGFUN6] Private slot <slot-name> of class <class-name> cannot be accessed directly by handlers attached to class <class-name>
A subclass which inherits private slots from a superclass may not access those slots using the ?self variable. This error can also occur when a superclass tries to access via dynamic-put or dynamic-get a private slot in a subclass.
Example:
CLIPS> (defclass FOO (is-a USER) (role concrete) (slot x))
CLIPS> (defclass BAR (is-a FOO))
CLIPS> (defmessage-handler BAR yak () ?self:x)
[MSGFUN7] Unrecognized message-handler type in defmessage-handler.
Allowed message-handler types include primary, before, after, and around.
Example:
CLIPS> (defmessage-handler USER foo behind ())
[MSGFUN8] Unable to delete message-handler(s) from class <name>.
This error occurs when an attempt is made to delete a message-handler attached to a class for which any of the message-handlers are executing.
Example:
CLIPS> (reset)
CLIPS>
(defmessage-handler INITIAL-OBJECT error ()
(undefmessage-handler INITIAL-OBJECT error primary))
CLIPS> (send [initial-object] error)
[MSGPASS1] Shadowed message-handlers not applicable in current context.
No shadowed message-handler is available when the function call-next-handler or override-next-handler is called.
Example:
CLIPS> (call-next-handler)
[MSGPASS2] No such instance <name> in function <name>.
This error occurs when the named function cannot find the specified instance.
Example:
CLIPS> (instance-address [bogus-instance])
[MSGPASS3] Static reference to slot <name> of class <name> does not apply to <instance-name> of <class-name>.
This error occurs when a static reference to a slot in a superclass by a message-handler attached to that superclass is incorrectly applied to an instance of a subclass which redefines that slot. Static slot references always refer to the slot defined in the class to which the message-handler is attached.
Example:
CLIPS>
(defclass A (is-a USER)
(slot foo))
CLIPS>
(defclass B (is-a A)
(role concrete)
(slot foo))
CLIPS>
(defmessage-handler A access-foo ()
?self:foo)
CLIPS> (make-instance b of B)
[b]
CLIPS> (send [b] access-foo)
[MSGPSR1] A class must be defined before its message-handlers.
A message-handler can only be attached to an existing class.
Example:
CLIPS> (defmessage-handler bogus-class foo ())
[MSGPSR2] Cannot (re)define message-handlers during execution of other message-handlers for the same class.
No message-handlers for a class can be loaded while any current message-handlers attached to the class are executing.
Example:
CLIPS> (defclass A (is-a USER))
CLIPS> (make-instance a of A)
[a]
CLIPS>
(defmessage-handler A build-new ()
(build “(defmessage-handler A new ())”))
CLIPS> (send [a] build-new)
[MSGPSR3] System message-handlers may not be modified.
There are four primary message-handlers attached to the class USER which cannot be modified: init, delete, create and print.
Example:
CLIPS> (defmessage-handler USER init ())
[MSGPSR4] Illegal slot reference in parameter list.
Direct slot references are allowed only within message-handler bodies.
Example:
CLIPS> (defmessage-handler USER foo (?self:bar))
[MSGPSR5] Active instance parameter cannot be changed.
?self is a reserved parameter for the active instance.
Example:
CLIPS>
(defmessage-handler USER foo ()
(bind ?self 1))
[MSGPSR6] No such slot <name> in class <name> for ?self reference.
The symbol following the ?self: reference must be a valid slot for the class.
Example:
CLIPS> (defclass FOO (is-a USER) (role concrete) (slot x))
CLIPS> (defmessage-handler FOO bar () ?self:y)
[MSGPSR7] Illegal value for ?self reference.
The symbol following the ?self: reference must be a symbol.
Example:
CLIPS> (defclass FOO (is-a USER) (role concrete) (slot x))
CLIPS> (defmessage-handler FOO bar () ?self:7)
[MSGPSR8] Message-handlers cannot be attached to the class <name>.
Message-handlers cannot be attached to the INSTANCE, INSTANCE-ADDRESS, or INSTANCE-NAME classes.
Example:
CLIPS> (defmessage-handler INSTANCE foo ())
[MULTIFUN1] Multifield index <index> out of range 1..<end range> in function <name>
or
[MULTIFUN1] Multifield index range <start>…<end> out of range 1..<end range> in function <name>
This error occurs when a multifield manipulation function is passed a single index or range of indices that does not fall within the specified range of allowed indices.
Example:
CLIPS> (delete$ (create$ a b c) 4 4)
[MULTIFUN2] Cannot rebind field variable in function progn$.
The field variable (if specified) cannot be rebound within the body of the progn$ function.
Example:
CLIPS> (progn$ (?field (create$ a)) (bind ?field 3))
[OBJRTBLD1] No objects of existing classes can satisfy pattern.
No objects of existing classes could possibly satisfy the pattern. This error usually occurs when a restriction placed on the is-a attribute is incompatible with slot restrictions before it in the pattern.
Example:
CLIPS> (defclass A (is-a INITIAL-OBJECT) (slot foo))
CLIPS> (defrule error (object (foo ?) (is-a ~A)) =>)
[OBJRTBLD2] No objects of existing classes can satisfy <attribute-name> restriction in object pattern.
The restrictions on <attribute> are such that no objects of existing classes (which also satisfy preceding restrictions) could possibly satisfy the pattern.
Example:
CLIPS> (defrule error (object (bad-slot ?)) =>)
[OBJRTBLD3] No objects of existing classes can satisfy pattern #<pattern-num>.
No objects of existing classes could possibly satisfy the pattern. This error occurs when the constraints for a slot as given in the defclass(es) are incompatible with the constraints imposed by the pattern.
Example:
CLIPS>
(defclass FOO (is-a INITIAL-OBJECT)
(slot bar (type INTEGER)))
CLIPS>
(defclass BAR (is-a INITIAL-OBJECT)
(slot bar (type SYMBOL))
(slot woz))
CLIPS>
(defrule error
(x abc)
(object (bar 100) (woz ?))
(y def)
=>)
[OBJRTBLD4] Multiple restrictions on attribute <attribute-name> not allowed.
Only one restriction per attribute is allowed per object pattern.
Example:
CLIPS> (defrule error (object (is-a ?) (is-a ?)) =>)
[OBJRTBLD5] Undefined class in object pattern.
Object patterns are applicable only to classes of objects which are already defined.
Example:
CLIPS> (defrule error (object (is-a BOGUS)) =>)
[OBJRTMCH1] This error occurred in the object pattern network
Currently active instance: <instance-name>
Problem resides in slot <slot name> field #<field-index>
Of pattern #<pattern-number> in rule(s):
<problem-rules>+
This error pinpoints other evaluation errors associated with evaluating an expression within the object pattern network. The specific pattern and field of the problem rules are identified.
[PATTERN1] The symbol <symbol name> has special meaning and may not be used as a <use name>.
Certain keywords have special meaning to CLIPS and may not be used in situations that would cause an ambiguity.
Example:
CLIPS> (deftemplate exists (slot x))
[PATTERN2] Single and multifield constraints cannot be mixed in a field constraint
Single and multifield variable constraints cannot be mixed in a field constraint (this restriction does not include variables passed to functions with the predicate or return value constraints).
Example:
CLIPS> (defrule foo (a ?x $?y ?x&~$?y) =>)
[PRCCODE1] Attempted to call a <construct> which does not exist.
In a CLIPS configuration without deffunctions and/or generic functions, an attempt was made to call a deffunction or generic function from a binary image generated by the bsave command.
[PRCCODE2] Functions without a return value are illegal as <construct> arguments.
An evaluation error occurred while examining the arguments for a deffunction, generic function or message.
Example:
CLIPS> (defmethod foo (?a))
CLIPS> (foo (instances))
[PRCCODE3] Undefined variable <name> referenced in <where>.
Local variables in the actions of a deffunction, method, message-handler, or defrule must reference parameters, variables bound within the actions with the bind function, or variables bound on the LHS of a rule.
Example:
CLIPS> (defrule foo => (+ ?a 3))
[PRCCODE4] Execution halted during the actions of <construct> <name>.
This error occurs when the actions of a rule, deffunction, generic function method or message-handler are prematurely aborted due to an error.
[PRCCODE5] Variable <name> unbound [in <construct> <name>].
This error occurs when local variables in the actions of a deffunction, method, message-handler, or defrule becomes unbound during execution as a result of calling the bind function with no arguments.
Example:
CLIPS> (deffunction foo () (bind ?a) ?a)
CLIPS> (foo)
[PRCCODE6] This error occurred while evaluating arguments for the <construct> <name>.
An evaluation error occurred while examining the arguments for a deffunction, generic function method or message-handler.
Example:
CLIPS> (deffunction foo (?a))
CLIPS> (foo (+ (eval “(gensym)”) 2))
[PRCCODE7] Duplicate parameter names not allowed.
Deffunction, method or message-handler parameter names must be unique.
Example:
CLIPS> (defmethod foo ((?x INTEGER) (?x FLOAT)))
[PRCCODE8] No parameters allowed after wildcard parameter.
A wildcard parameter for a deffunction, method or message-handler must be the last parameter.
Example:
CLIPS> (defmethod foo (($?x INTEGER) (?y SYMBOL)))
[PRCDRPSR1] Cannot rebind count variable in function loop-for-count.
The special variable ?count cannot be rebound within the body of the loop-for-count function.
Example:
CLIPS> (loop-for-count (?count 10) (bind ?count 3))
[PRCDRPSR2] The return function is not valid in this context.
or
[PRCDRPSR2] The break function is not valid in this context.
The return and break functions can only be used within certain contexts (e.g. the break function can only be used within a while loop and certain instance set query functions).
Example:
CLIPS> (return 3)
[PRCDRPSR3] Duplicate case found in switch function.
A case may be specified only once in a switch statement.
Example:
CLIPS> (switch a (case a then 8) (case a then 9))
[PRNTUTIL1] Unable to find <item> <item-name>
This error occurs when CLIPS cannot find the named item (check for typos).
[PRNTUTIL2] Syntax Error: Check appropriate syntax for <item>
This error occurs when the appropriate syntax is not used.
Example:
CLIPS> (if (> 3 4))
[PRNTUTIL3]
*** CLIPS SYSTEM ERROR ***
ID = <error-id>
CLIPS data structures are in an inconsistent or corrupted state.
This error may have occurred from errors in user defined code.
**************************
This error indicates an internal problem within CLIPS (which may have been caused by user defined functions or other user code). If the problem cannot be located within user defined code, then the <error-id> should be reported.
[PRNTUTIL4] Unable to delete <item> <item-name>
This error occurs when CLIPS cannot delete the named item (e.g. a construct might be in use). One example which will cause this error is an attempt to delete a deffunction or generic function which is used in another construct (such as the RHS of a defrule or a default-dynamic facet of a defclass slot).
[PRNTUTIL5] The <item> has already been parsed.
This error occurs when CLIPS has already parsed an attribute or declaration.
[PRNTUTIL6] Local variables cannot be accessed by <function or construct>.
This error occurs when a local variable is used by a function or construct that cannot use global variables.
Example:
CLIPS> (deffacts info (fact ?x))
[PRNTUTIL7] Attempt to divide by zero in <function-name> function.
This error occurs when a function attempts to divide by zero.
Example:
CLIPS> (/ 3 0)
[ROUTER1] Logical name <logical_name> was not recognized by any routers
This error results because “Hello” is not recognized as a valid router name.
Example:
CLIPS> (printout “Hello” crlf)
[RULECSTR1] Variable <variable name> in CE #<integer> slot <slot name>
has constraint conflicts which make the pattern unmatchable.
or
[RULECSTR1] Variable <variable name> in CE #<integer> field #<integer>
has constraint conflicts which make the pattern unmatchable.
or
[RULECSTR1] CE #<integer> slot <slot name>
has constraint conflicts which make the pattern unmatchable.
or
[RULECSTR1] CE #<integer> field #<integer>
has constraint conflicts which make the pattern unmatchable.
This error occurs when slot value constraints (such as allowed types) prevents any value from matching the slot constraint for a pattern.
Example:
CLIPS> (deftemplate foo (slot x (type SYMBOL)))
CLIPS> (deftemplate bar (slot x (type FLOAT)))
CLIPS> (defrule yak (foo (x ?x)) (bar (x ?x)) =>)
[RULECSTR2] Previous variable bindings of <variable name> caused the type restrictions
for argument #<integer> of the expression <expression>
found in CE#<integer> slot <slot name> to be violated.
This error occurs when previous variable bindings and constraints prevent a variable from containing a value which satisfies the type constraints for one of a function?s parameters.
Example:
CLIPS> (deftemplate foo (slot x (type SYMBOL)))
CLIPS> (defrule bar (foo (x ?x&:(> ?x 3))) =>)
[RULECSTR3] Previous variable bindings of <variable name> caused the type restrictions
for argument #<integer> of the expression <expression>
found in the rule’s RHS to be violated.
This error occurs when previous variable bindings and constraints prevent a variable from containing a value which satisfies the type constraints for one of a function?s parameters.
Example:
CLIPS> (deftemplate foo (slot x (type SYMBOL)))
CLIPS> (defrule bar (foo (x ?x)) => (printout t (+ ?x 1) crlf))
[RULELHS1] The logical CE cannot be used with a not/exists/forall CE.
Logical CEs can be placed outside, but not inside, a not/exists/forall CE.
Example:
CLIPS> (defrule error (not (logical (x))) =>)
[RULELHS2] A pattern CE cannot be bound to a pattern-address within a not CE
This is an illegal operation and results in an error message.
Example:
CLIPS> (defrule error (not ?f <- (fact)) =>)
[RULEPSR1] Logical CEs must be placed first in a rule
If logical CEs are used, then the first CE must be a logical CE.
Example:
CLIPS> (defrule error (a) (logical (b)) =>)
[RULEPSR2] Gaps may not exist between logical CEs
Logical CEs found within a rule must be contiguous.
Example:
CLIPS> (defrule error (logical (a)) (b) (logical (c)) =>)
[STRNGFUN1] Function build does not work in run time modules.
or
[STRNGFUN1] Function eval does not work in run time modules.
The build and eval functions do not work in run time modules because the code required for parsing is not available.
[STRNGFUN2] Some variables could not be accessed by the eval function.
Local variables cannot be accessed by the eval function.
Example:
CLIPS> (eval “?x”)
[SYSDEP1] No file found for -f option
This message occurs if the -f option is used when executing CLIPS, but no arguments are provided.
Example:
clips -f
[TEXTPRO1] Could not open file <file-name>.
This error occurs when the external text-processing system command fetch encounters an error when loading a file.
Example:
CLIPS> (fetch ?bogus.txt?E
[TMPLTDEF1] Invalid slot <slot name> not defined in corresponding deftemplate <deftemplate name>
The slot name supplied does not correspond to a slot name defined in the corre?sponding deftemplate
Example:
CLIPS> (deftemplate example (slot x))
CLIPS> (defrule error (example (z 3)) =>)
[TMPLTDEF2] The single field slot <slot name> can only contain a single field value.
If a slot definition is specified in a template pattern or fact, the contents of the slot must be capable of matching against or evaluating to a single value.
Example:
CLIPS> (deftemplate example (slot x))
CLIPS> (assert (example (x)))
[TMPLTFUN1] Fact-indexes can only be used by <command name> as a top level command.
Fact indexes may only be used with the modify and duplicate commands when the command is issued from the top-level command prompt.
Example:
CLIPS> (defrule foo => (modify 1 (x 3))
[TMPLTFUN2] Attempted to assert a multifield value into the single field slot <slot name> of deftemplate <deftemplate name>.
A multifield value cannot be stored in a single field slot.
Example:
CLIPS> (deftemplate foo (slot x))
CLIPS>
(defrule foo
=>
(bind ?x (create$ a b))
(assert (foo (x ?x))))
CLIPS> (reset)
CLIPS> (run)
[TMPLTRHS1] Slot <slot name> requires a value because of its (default ?NONE) attribute.
The (default ?NONE) attribute requires that a slot value be supplied whenever a new fact is created.
Example:
CLIPS> (deftemplate foo (slot x (default ?NONE)))
CLIPS> (assert (foo))
Appendix G: CLIPS BNF ===========
Data Types
<symbol> ::= A valid symbol as specified
in section 2.3.1
<string> ::= A valid string as specified
in section 2.3.1
<float> ::= A valid float as specified
in section 2.3.1
<integer> ::= A valid integer as specified
in section 2.3.1
<instance-name> ::= A valid instance-name as specified
in section 2.3.1
<number> ::= <float> | <integer>
<lexeme> ::= <symbol> | <string>
<constant> ::= <symbol> | <string> | <integer> |
<float> | <instance-name>
<comment> ::= <string>
<variable-symbol> ::= A symbol beginning with an
alphabetic character
<function-name> ::= Any symbol which corresponds to a
system or user defined function, a
deffunction name, or a defgeneric
name
<file-name> ::= A symbol or string which is a valid
file name (including path
information) for the operating
system under which CLIPS is running
<slot-name> ::= A valid deftemplate slot name
<…-name> ::= A <symbol> where the ellipsis
indicate what the symbol represents.
For example, <rule-name> is a symbol
which represents the name of a rule.
Variables and Expressions
<single-field-variable> ::= ?<variable-symbol>
<multifield-variable> ::= $?<variable-symbol>
<global-variable> ::= ?*<symbol>*
<variable> ::= <single-field-variable> |
<multifield-variable> |
<global-variable>
<function-call> ::= (<function-name> <expression>*)
<expression> ::= <constant> | <variable> |
<function-call>
<action> ::= <expression>
<…-expression> ::= An <expression> which returns
the type indicated by the
ellipsis. For example,
<integer-expression> should
return an integer.
Constructs
<CLIPS-program> ::= <construct>*
<construct> ::= <deffacts-construct> |
<deftemplate-construct> |
<defglobal-construct> |
<defrule-construct> |
<deffunction-construct> |
<defgeneric-construct> |
<defmethod-construct> |
<defclass-construct> |
<definstance-construct> |
<defmessage-handler-construct> |
<defmodule-construct>
Deffacts Construct
Deftemplate Construct
<deftemplate-construct>
::= (deftemplate <deftemplate-name>
[<comment>]
<slot-definition>*)
<slot-definition> ::= <single-slot-definition> |
<multislot-definition>
<single-slot-definition>
::= (slot <slot-name> <template-attribute>*)
<multislot-definition>
::= (multislot <slot-name>
<template-attribute>*)
<template-attribute>
::= <default-attribute> |
<constraint-attribute>
<default-attribute>
::= (default ?DERIVE | ?NONE | <expression>*) |
(default-dynamic <expression>*)
Fact Specification
<RHS-pattern> ::= <ordered-RHS-pattern> |
<template-RHS-pattern>
<ordered-RHS-pattern> ::= (<symbol> <RHS-field>+)
<template-RHS-pattern> ::= (<deftemplate-name> <RHS-slot>*)
<RHS-slot> ::= <single-field-RHS-slot> |
<multifield-RHS-slot>
<single-field-RHS-slot> ::= (<slot-name> <RHS-field>)
<multifield-RHS-slot> ::= (<slot-name> <RHS-field>*)
<RHS-field> ::= <variable> |
<constant> |
<function-call>
Defrule Construct
<defrule-construct> ::= (defrule <rule-name> [<comment>]
[<declaration>]
<declaration> ::= (declare <rule-property>+)
<rule-property> ::= (salience <integer-expression>) |
(auto-focus <boolean-symbol>)
<boolean-symbol> ::= TRUE | FALSE
<conditional-element> ::= <pattern-CE> |
<assigned-pattern-CE> |
<not-CE> | <and-CE> | <or-CE> |
<logical-CE> | <test-CE> |
<exists-CE> | <forall-CE>
<pattern-CE> ::= <ordered-pattern-CE> |
<template-pattern-CE> |
<object-pattern-CE>
<assigned-pattern-CE> ::= <single-field-variable> <- <pattern-CE>
<not-CE> ::= (not <conditional-element>)
<and-CE> ::= (and <conditional-element>+)
<or-CE> ::= (or <conditional-element>+)
<logical-CE> ::= (logical <conditional-element>+)
<test-CE> ::= (test <function-call>)
<exists-CE> ::= (exists <conditional-element>+)
<forall-CE> ::= (forall <conditional-element>
<conditional-element>+)
<ordered-pattern-CE> ::= (<symbol> <constraint>*)
<template-pattern-CE> ::= (<deftemplate-name> <LHS-slot>*)
<object-pattern-CE> ::= (object <attribute-constraint>*)
<attribute-constraint> ::= (is-a <constraint>) |
(name <constraint>) |
(<slot-name> <constraint>*)
<LHS-slot> ::= <single-field-LHS-slot> |
<multifield-LHS-slot>
<single-field-LHS-slot> ::= (<slot-name> <constraint>)
<multifield-LHS-slot> ::= (<slot-name> <constraint>*)
<constraint> ::= ? | $? | <connected-constraint>
<connected-constraint>
::= <single-constraint> |
<single-constraint> & <connected-constraint> |
<single-constraint> | <connected-constraint>
<single-constraint> ::= <term> | ~<term>
<term> ::= <constant> |
<single-field-variable> |
<multifield-variable> |
:<function-call> |
=<function-call>
Defglobal Construct
<defglobal-construct> ::= (defglobal [<defmodule-name>]
<global-assignment>*)
<global-assignment> ::= <global-variable> = <expression>
<global-variable> ::= ?*<symbol>*
Deffunction Construct
<deffunction-construct>
::= (deffunction <name> [<comment>]
(<regular-parameter>* [<wildcard-parameter>])
<action>*)
<regular-parameter> ::= <single-field-variable>
<wildcard-parameter> ::= <multifield-variable>
Defgeneric Construct
<defgeneric-construct> ::= (defgeneric <name> [<comment>])
Defmethod Construct
<defmethod-construct>
::= (defmethod <name> [<index>] [<comment>]
(<parameter-restriction>*
[<wildcard-parameter-restriction>])
<action>*)
<parameter-restriction>
::= <single-field-variable> |
(<single-field-variable> <type>* [<query>])
<wildcard-parameter-restriction>
::= <multifield-variable> |
(<multifield-variable> <type>* [<query>])
<type> ::= <class-name>
<query> ::= <global-variable> | <function-call>
Defclass Construct
<defclass-construct> ::= (defclass <name> [<comment>]
(is-a <superclass-name>+)
[<role>]
[<pattern-match-role>]
<slot>*
<handler-documentation>*)
<role> ::= (role concrete | abstract)
<pattern-match-role>
::= (pattern-match reactive | non-reactive)
<slot> ::= (slot <name> <facet>*) |
(single-slot <name> <facet>*) |
(multislot <name> <facet>*)
<facet> ::= <default-facet> | <storage-facet> |
<access-facet> | <propagation-facet> |
<source-facet> | <pattern-match-facet> |
<visibility-facet> | <create-accessor-facet>
<override-message-facet> | <constraint-attribute>
<default-facet> ::=
(default ?DERIVE | ?NONE | <expression>*) |
(default-dynamic <expression>*)
<storage-facet> ::= (storage local | shared)
<access-facet>
::= (access read-write | read-only | initialize-only)
<propagation-facet> ::= (propagation inherit | no-inherit)
<source-facet> ::= (source exclusive | composite)
<pattern-match-facet>
::= (pattern-match reactive | non-reactive)
<visibility-facet> ::= (visibility private | public)
<create-accessor-facet>
::= (create-accessor ?NONE | read | write | read-write)
<override-message-facet>
::= (override-message ?DEFAULT | <message-name>)
<handler-documentation>
::= (message-handler <name> [<handler-type>])
<handler-type> ::= primary | around | before | after
Defmessage-handler Construct
<defmessage-handler-construct>
::= (defmessage-handler <class-name>
<message-name> [<handler-type>] [<comment>]
(<parameter>* [<wildcard-parameter>])
<action>*)
<handler-type> ::= around | before | primary | after
<parameter> ::= <single-field-variable>
<wildcard-parameter> ::= <multifield-variable>
Definstances Construct
<definstances-construct>
::= (definstances <definstances-name>
[active] [<comment>]
<instance-template>*)
<instance-template> ::= (<instance-definition>)
<slot-override> ::= (<slot-name-expression> <expression>*)
Defmodule Construct
<defmodule-construct> ::= (defmodule <module-name> [<comment>]
<port-specification>*)
<port-specification> ::= (export <port-item>) |
(import <module-name> <port-item>)
<port-item> ::= ?ALL |
?NONE |
<port-construct> ?ALL |
<port-construct> ?NONE |
<port-construct> <construct-name>+
<port-construct> ::= deftemplate | defclass |
defglobal | deffunction |
defgeneric
Constraint Attributes
<constraint-attribute>
::= <type-attribute>?|
<allowed-constant-attribute> |
<range-attribute> |
<cardinality-attribute>
<type-attribute> ::= (type <type-specification>)
<type-specification> ::= <allowed-type>+ | ?VARIABLE
<allowed-type> ::= SYMBOL | STRING | LEXEME |
INTEGER | FLOAT | NUMBER |
INSTANCE-NAME | INSTANCE-ADDRESS |
INSTANCE | EXTERNAL-ADDRESS |
FACT-ADDRESS
<allowed-constant-attribute>
::= (allowed-symbols?<symbol-list>) |
(allowed-strings <string-list>) |
(allowed-lexemes <lexeme-list> |
(allowed-integers?<integer-list>) |
(allowed-floats?<float-list>) |
(allowed-numbers?<number-list>) |
(allowed-instance-names <instance-list>) |
(allowed-classes <class-name-list>) |
(allowed-values?<value-list>)
<symbol-list> ::= <symbol>+ | ?VARIABLE
<string-list> ::= <string>+ | ?VARIABLE
<lexeme-list> ::= <lexeme>+ | ?VARIABLE
<integer-list> ::= <integer>+ | ?VARIABLE
<float-list> ::= <float>+ | ?VARIABLE
<number-list> ::= <number>+ | ?VARIABLE
<instance-name-list> ::= <instance-name>+ | ?VARIABLE
<class-name-list> ::= <class-name>+ | ?VARIABLE
<value-list> ::= <constant>+ | ?VARIABLE
<range-attribute> ::= (range <range-specification>
<range-specification>)
<range-specification> ::= <number> | ?VARIABLE
<cardinality-attribute>
::= (cardinality <cardinality-specification>
<cardinality-specification>)
<cardinality-specification>
::= <integer> | ?VARIABLE
Appendix H: Reserved Function Names =======================
This appendix lists all of the functions provided by either standard CLIPS or various CLIPS extensions. They should be considered reserved function names, and users should not create user-defined functions with any of these names.
!=
*
**
/
<
<=
<>
=
>
>=
abs
acos
acosh
acot
acoth
acsc
acsch
active-duplicate-instance
active-initialize-instance
active-make-instance
active-message-duplicate-instance
active-message-modify-instance
active-modify-instance
agenda
and
any-instancep
apropos
asec
asech
asin
asinh
assert
assert-string
atan
atanh
batch
batch*
bind
bload
bload-instances
break
browse-classes
bsave
bsave-instances
build
call-next-handler
call-next-method
call-specific-method
class
class-abstractp
class-existp
class-reactivep
class-slots
class-subclasses
class-superclasses
clear
clear-focus-stack
close
conserve-mem
constructs-to-c
cos
cosh
cot
coth
create$
csc
csch
defclass-module
deffacts-module
deffunction-module
defgeneric-module
defglobal-module
definstances-module
defrule-module
deftemplate-module
deg-grad
deg-rad
delayed-do-for-all-instances
delete$
delete-instance
dependencies
dependents
describe-class
direct-mv-delete
direct-mv-insert
direct-mv-replace
div
do-for-all-instances
do-for-instance
dribble-off
dribble-on
duplicate
duplicate-instance
duplicate-instance
dynamic-get
dynamic-put
edit
eq
eval
evenp
exit
exp
expand$
explode$
fact-existp
fact-index
fact-relation
fact-slot-names
fact-slot-value
facts
fetch
find-all-instances
find-instance
first$
float
floatp
focus
format
gensym
gensym*
get
get-auto-float-dividend
get-current-module
get-defclass-list
get-deffacts-list
get-deffunction-list
get-defgeneric-list
get-defglobal-list
get-definstances-list
get-defmessage-handler-list
get-defmethod-list
get-defmodule-list
get-defrule-list
get-deftemplate-list
get-dynamic-constraint-checking
get-fact-duplication
get-fact-list
get-focus
get-focus-stack
get-function-restrictions
get-incremental-reset
get-method-restrictions
get-reset-globals
get-salience-evaluation
get-sequence-operator-recognition
get-static-constraint-checking
get-strategy
grad-deg
halt
if
implode$
init-slots
initialize-instance
initialize-instance
insert$
instance-address
instance-addressp
instance-existp
instance-name
instance-name-to-symbol
instance-namep
instancep
instances
integer
integerp
length
length$
lexemep
list-defclasses
list-deffacts
list-deffunctions
list-defgenerics
list-defglobals
list-definstances
list-defmessage-handlers
list-defmethods
list-defmodules
list-defrules
list-deftemplates
list-focus-stack
list-watch-items
load
load*
load-facts
load-instances
log
log10
loop-for-count
lowcase
make-instance
make-instance
matches
max
mem-requests
mem-used
member
member$
message-duplicate-instance
message-duplicate-instance
message-handler-existp
message-modify-instance
message-modify-instance
min
mod
modify
modify-instance
modify-instance
multifieldp
mv-append
mv-delete
mv-replace
mv-slot-delete
mv-slot-insert
mv-slot-replace
mv-subseq
neq
next-handlerp
next-methodp
not
nth
nth$
numberp
object-pattern-match-delay
oddp
open
options
or
override-next-handler
override-next-method
pi
pointerp
pop-focus
ppdefclass
ppdeffacts
ppdeffunction
ppdefgeneric
ppdefglobal
ppdefinstances
ppdefmessage-handler
ppdefmethod
ppdefmodule
ppdefrule
ppdeftemplate
ppinstance
preview-generic
preview-send
primitives-info
print-region
printout
progn
progn$
put
rad-deg
random
read
readline
refresh
refresh-agenda
release-mem
remove
remove-break
rename
replace$
reset
rest$
restore-instances
retract
return
round
rule-complexity
rules
run
save
save-facts
save-instances
sec
sech
seed
send
sequencep
set-auto-float-dividend
set-break
set-current-module
set-dynamic-constraint-checking
set-fact-duplication
set-incremental-reset
set-reset-globals
set-salience-evaluation
set-sequence-operator-recognition
set-static-constraint-checking
set-strategy
setgen
show-breaks
show-defglobals
show-fht
show-fpn
show-joins
show-opn
sin
sinh
slot-allowed-values
slot-cardinality
slot-delete$
slot-direct-accessp
slot-direct-delete$
slot-direct-insert$
slot-direct-replace$
slot-existp
slot-facets
slot-initablep
slot-insert$
slot-publicp
slot-range
slot-replace$
slot-sources
slot-types
slot-writablep
sqrt
str-assert
str-cat
str-compare
str-explode
str-implode
str-index
str-length
stringp
sub-string
subclassp
subseq$
subset
subsetp
superclassp
switch
sym-cat
symbol-to-instance-name
symbolp
system
tan
tanh
time
toss
type
type
undefclass
undeffacts
undeffunction
undefgeneric
undefglobal
undefinstances
undefmessage-handler
undefmethod
undefrule
undeftemplate
unmake-instance
unwatch
upcase
watch
while
wordp
Appendix I: Bibliography of CLIPS Publications ==================================
Programming
Giarratano, J., and Riley, G. Expert Systems: Principles and Programming, 3rd Edition, Boston, PWS Publishing Company, 1998.
Gonzalez, A. J., and Dankel, D. D. Engineering of Knowledge-basedSystems: Theory and Practice, Prentice Hall, 1993.
Jackson, P. Introduction to Expert Systems, 3rd Edition, Reading, Addison-Wesley, 1998.
Reviews
Brooke, T. ?The Art of Production Systems,?E*AI Expert*, January 1992.
Brooke, T. ?Software Review,?E*AI Expert*, April 1988.
Golden, J. ?Shell Review Monthly,?E*AI Today*, March/April 1988.
Mettrey, W. ?A Comparative Evaluation of Expert System Tools,?E Computer, February 1991.
Popolizio, J. ?CLIPS: NASA?s COSMIC Shell,?E*Artificial Intelligence Research*, August 1, 1988.
Raeth, P. ?Two PC?based Expert System Shells for the First?time Developer,?E*Computer*, November 1988.
Overviews
Culbert, C., et al., ?A Solution to the Expert System Delivery Problem,?E Proceedings of the ISA/88, Houston, TX, October 1988.
Riley, G. ?C Language Integrated Production System,?Ein Encyclopedia of Computer Science and Technology, Volume 37. Edited by A. Kent and J.G. Williams. New York, Marcel Dekker, Inc., 1997.
Riley, G. ?Expert Systems Methodology,?Ein The Industrial Electronics Handbook. Edited by J.D. Irwin. Boca Raton, CRC Press, 1997.
Riley, G. ?CLIPS: An Expert System Building Tool,?E*Proceedings of the Technology 2001 Conference*, San Jose, CA, December 1991.
Riley, G. ?CLIPS: A Tool for the Development and Delivery of Expert Systems,?E*Proceedings of the Technology 2000 Conference*, Washington, DC, November 1990.
Riley G., and Donnell, B. ?Advanced CLIPS Capabilities,?E*Proceedings of The Fourth Annual Workshop on Space Operations Applications and Research (SOAR ?E0)*, Albuquerque, NM, June 1990.
Riley, G., et al. ?CLIPS: An Expert System Tool for Training, Development, and Delivery,?Ein Intelligent Systems Review, Volume 1, Number 1, Fall 1988.
Riley, G., et al., ?CLIPS: An Expert System Tool for Delivery and Training,?E*Proceedings of the Third Conference on Artificial Intelligence for Space Applications*, Huntsville, AL, November 1987.
Applications
Carreno, L. A. and Steel, R. A. ?Life Insurance Risk Assessment using a Fuzzy Logic Expert System,?E*Proceedings of the North American Fuzzy Logic Processing Society (NAFIPS 1992)*, Houston, TX, December 1992.
Cheatham, J. B., et al. ?A Multi?Sensor System for Robotics Proximity Operations,?E*Proceedings of The Second Annual Workshop on Space Operations Automation and Robotics (SOAR ?E8)*, Albuquerque, NM, July 1988.
Chen, Y. ?Applying Knowledge?Based Expert System to Meat Grading,?E Proceedings of The Annual AI Systems in Government Conference, Washington, D.C., March 1989.
?CLIPS: A NASA Developed Expert System Tool,?E*NASA Tech Briefs*, November/December 1987.
Dutton, T. ?HUB SIAASHING: A Knowledge?Based System for Severe, Temporary Airline Schedule Reduction,?E*Innovative Applications of Artificial Intelligence 4*, Klahr, Philip, and Scott, A. Carlisle ed., 1992.
Ehler, G. B. ?A Multiple Knowledge-Based Spatial Decision Support System for Industrial Site Selection,?EM.S. Thesis, Department of Geography, University of South Carolina, Columbia, SC.
Fink, P., and Herren, L. T. ?An Intelligent Tutoring System to Teach Interdependent Cognitive and High Performance Skills,?E*Proceedings of Contributed Sessions 1991 Conference on Intelligent Computer Aided Training*, Houston, TX, November 1991.
Fink, P. ?NESSUS/EXPERT: Bridging the Gap between Artificial Intelligence and FORTRAN,?E*Proceedings of The Second Annual Workshop on Space Operations Automation and Robotics (SOAR ?E8)*, Albuquerque, NM, July 1988.
Flamm, R. O., et al. ?The Integrated Southern Pine Beetle Expert System: ISPBEX,?E*Expert Systems with Applications*, Vol. 2, 1991.
Franier, R., et al. ?PI?in?a?Box: A Knowledge?based System for Space Science Experimentation,?E*Proceedings of the Fifth Innovative Applications of Artificial Intelligence Conference*, July 11?E5, 1993, Washington, D.C.
Frainier, R., et al. ?PI-in-a-Box: A Knowledge-Based System for Space Science Experimentation,?E*AI magazine*, Volume 15, No. 1, Spring, 1994.
Frainier, R., et al. ?PI in the Sky: The Astronaut Science Advisor on SLS-2,?E*Proceedings of The Seventh Annual Workshop on Space Operations Applications and Research (SOAR ?E3)*, Houston, TX, August 1993.
Germain, D., and Desrosiers, S. ?Turning Up the Heat on Space Station Training: The Active Thermal Control System ICAT,?E*Proceedings of Contributed Sessions 1991 Conference on Intelligent Computer Aided Training*, Houston, TX, November 1991.
Grinstein, G. G., et al. ?Virtual Environment Architecture for Rapid Application Development,?E*Proceedings of The Contributed Sessions 1993 Conference on Intelligent Computer Aided Training and Virtual Environment Technology* (ICAT-VET ?E3), Houston, TX, May 1993.
Haymann?Haber, G., et al. ?An Expert System to Advise Astronauts During Experiments: The Protocol Manager Module,?E*Proceedings of The Third Annual Workshop on Space Operations Automation and Robotics (SOAR ?E9)*, Houston, TX, July 1989.
Hill, T., and Faltisco, R. ?Intelligent Fault Management for the Space Station Active Thermal Control System,?E*Proceedings of The Fifth Annual Workshop on Space Operations Applications and Research (SOAR ?E1)*, Houston, TX, July 1991.
Hipwell, D. P. ?Developing Realistic Cooperative Behaviors for Autonomous Agents in Air Combat Simuation,?EM.S. Thesis, Air Force Institute of Technology, Wright Patternson AFB, Ohio, 1993.
Hughes, P. M. ?CLEAR: Automating Control Centers with Expert System Technology,?E*Proceedings of The Third Annual Workshop on Space Operations Automation and Robotics (SOAR ?E9)*, Houston, TX, July 1989.
Johnson, W. B., et al. ?An Intelligent Tutoring System for Space Shuttle Diagnosis,?E*Proceedings of The Second Annual Workshop on Space Operations Automation and Robotics (SOAR ?E8)*, Albuquerque, NM, July 1988.
Kahn, M. G., et al. ?An Expert System for Culture-Based Infection Control Surveillance,?E*Proceedings of The Seventeenth Annual Symposium on Computer Applications in Medical Care* (SCAMC ?E3), Washington, D.C., October 1993.
Kingston, J. ?Pragmatic KADS: A methodological approach to a small knowledge based systems project,?E*Expert Systems: The International Journal of Knowledge Engineering*, 4, 4, November 1992.
Kosta, C. P., and Krolak, P. D. ?Rapid Prototyping 3D Virtual World Interfaces within a Virtual Factory Environment,?E*Proceedings of The Contributed Sessions 1993 Conference on Intelligent Computer Aided Training and Virtual Environment Technology* (ICAT-VET ?E3), Houston, TX, May 1993.
Kosta, C. P., and Krolak, P. D. ?An Artificial Reality Environment for Remote Factory Control and Monitoring,?E*Vision 21: Interdisciplinary Science and Engineering in the Era of Cyberspace*, NASA/Lewis Research Center, December 1993.
Kovarik, V. J. ?Autonomously Acquiring Declarative and Procedural Domain Knowledge for ICAT Systems,?E*Proceedings of The Contributed Sessions 1993 Conference on Intelligent Computer Aided Training and Virtual Environment Technology* (ICAT-VET ?E3), Houston, TX, May 1993.
Lauriente, M., et al. ?Diagnosing Anomalies of Spacecraft for Space Maintenance and Servicing,?E*Proceedings of The Seventh Annual Workshop on Space Operations Applications and Research (SOAR ?E3)*, Houston, TX, August 1993.
Lee, L., and Hill, R. W., ?Process Control and Recovery in the Link Monitor and Control Operator Assistant,?E*Proceedings of The Sixth Annual Workshop on Space Operations Applications and Research (SOAR ?E2)*, Houston, TX, August 1992.
Leinweber, D. ?Finance,?E*Expert Systems and Artificial Intelligence: Applications and Management,* Howard W. Sams & Company, Bartee, T. C. ed., 1988.
Loftin, K. C., et al. ?The Application of Integrated Knowledge?Based Systems for the Biomedical Risk Accessment Intelligent Network (BRAIN),?E Proceedings of Technology 2002: The Third National Technology Transfer Conference and Exposition, Washington D.C., February 1993.
Loftin, R. B., and Savely, R.T. ?Intelligent Computer Aided Training and Tutoring,?E*Proceedings of the Technology 2000 Conference*, Washington, DC, November 1990.
Loftin, R. B., et al. ?An Intelligent Training System for Space Shuttle Flight Controllers,?E*Innovative Applications of Artificial Intelligence*, 1989, AAAI Press/The MIT Press, Menlo Press, Schoor, Herbert, and Rappaport, Alain ed.
Loftin, R. B., et al. ?An Intelligent Training System for Payload?Assist Module Deploys,?E*Proceedings of The First Annual Workshop on Space Operations Automation and Robotics (SOAR ?E7)*, Houston, TX, August 1987.
Lucas, T. S., and Lewis, G. ?DISPLAVAL: An Expert System Approach for the Training of Display Builders,?E*Proceedings of Contributed Sessions 1991 Conference on Intelligent Computer Aided Training*, Houston, TX, November 1991.
McCarthy, L., et al. ?Spatial Considerations for Instructional Development in a Virtual Environment,?E*Proceedings of The Contributed Sessions 1993 Conference on Intelligent Computer Aided Training and Virtual Environment Technology* (ICAT-VET ?E3), Houston, TX, May 1993.
?Mission Accomplished,?E*NASA Tech Briefs*, September 1993.
Mitchell, P. ?An Expert System for Shuttle and Satellite Radar Tracker Scheduling,?E*Proceedings of The Second Annual Workshop on Space Operations Automation and Robotics (SOAR ?E8)*, Albuquerque, NM, July 1988.
Mitchell, R. ?Expert Systems and Air?Combat Simulation,?E*AI Expert*, September 1989.
Mortenson, P. ?Predicting Wind Shear from the Dispatch Office,?E*Airline Executive*, April 1988.
Mueller, S. ?Development of a Personal?Computer?Based Intelligent Tutoring System,?E*Proceedings of The Second Annual Workshop on Space Operations Automation and Robotics (SOAR ?E8)*, Albuquerque, NM, July 1988.
Muratore, J., et al. ?Space Shuttle Telemetry Monitoring,?E*Innovative Applications of Artificial Intelligence*, 1989, AAAI Press/The MIT Press, Menlo Press, Schoor, Herbert, and Rappaport, Alain ed.
Nash, J. ?Expert Systems: A New Partnership,?E*AI Expert*, December 1992.
Norton, J. E., et al. ?Microcomputer Intelligence for Technical Training (MITT): The Evolution of an Intelligent Tutoring System,?E*Proceedings of Contributed Sessions 1991 Conference on Intelligent Computer Aided Training,* Houston, TX, November 1991.
Proceedings of the First CLIPS Conference, Houston, Texas, August 1990.
Proceedings of the Second CLIPS Conference, Houston, Texas, September 1991.
Proceedings of the Third CLIPS Conference, Houston, Texas, September 1994.
Robey, B., et al. ?The DRAIR Advisor: A Knowledge?Based System for Materiel Deficiency Analysis,?E*Proceedings of the Fifth Innovative Applications of Artificial Intelligence Conference*, July 11?E5, 1993, Washington, D.C.
Robey, B., et al. ?DRAIR Advisor: A Knowledge-Based System for Materiel-Deficiency Analysis,?E*AI magazine*, Volume 15, No. 2, Summer, 1994.
Rolincik, M, et al. ?An On?line Expert System for Diagnosing Environmentally Induced Spacecraft Anomalies using CLIPS,?E*Proceedings of The Sixth Annual Workshop on Space Operations Applications and Research (SOAR ?E2)*, Houston, TX, August 1992.
Rolincik, M., et al. ?An Expert System for Diagnosing Environmentally Induced Spacecraft Anomolies,?E*Proceedings of The Fifth Annual Workshop on Space Operations Applications and Research (SOAR ?E1)*, Houston, TX, July 1991.
Saito, T., et al. ?Acquiring Knowledge within an ICAT (Intelligent Computer?Aided Training) Environment: Factors and Issues,?E*Proceedings of Contributed Sessions 1991 Conference on Intelligent Computer Aided Training*, Houston, TX, November 1991.
Saito, T., et al. ?On the Acquisition and Representation of Procedural Knowledge,?E*Proceedings of The Fifth Annual Workshop on Space Operations Applications and Research (SOAR ?E1)*, Houston, TX, July 1991.
Scholtz, T. ?The State Transition Diagram with Path Priority and it?s Applications,?EM.S. Thesis, Naval Postgraduate School, Monterey, CA, September 1993.
Schultz, R. D, and Stobie, I. ?The AI Bus Architecture for Distributed Knowledge?Based Systems,?E*Proceedings of The Fourth Annual Workshop on Space Operations Applications and Research (SOAR ?E0)*, Albuquerque, NM, June 1990.
Spelt, P. F. ?Learning by an Autonomous Robot at a Process Control Panel,?E*IEEE Expert*, Winter 1989.
Spinoff 1993, NASA, pp. 88, 102, 120?E21, 1994.
Spinoff 1992, NASA, p. 121, 1993.
Spinoff 1991, NASA, pp. 110?E11, 1992.
Swartz, M., et al. ?Intelligent Help for Radar Maintenance Troubleshooters,?E*Proceedings of Contributed Sessions 1991 Conference on Intelligent Computer Aided Training*, Houston, TX, November 1991.
Szatkowski, G. P., and Levin, B. E. ?Expert System Decision Support for Low?cost Launch Vehicle Operations,?E*Proceedings of The Fourth Annual Workshop on Space Operations Applications and Research (SOAR ?E0)*, Albuquerque, NM, June 1990.
Truszkowski, W. ?Advances in Knowledge?Based Software Engineering,?E Proceedings of the Technology 2001Conference, San Jose, CA, December 1991.
Wallfesh, S. K. ?Infantry Load Planning with LES,?E*Artificial Intelligence Applications for Logistics, Aerospace Systems, Robotics & Personnel,* American Defense Preparedness Association, WIlliamsburg, VA, 8?E0 March 1993.
Wang, L., and Bochsler, D. ?Space Shuttle Onboard Navigation Console Expert/Trainer System,?E*Proceedings of The First Annual Workshop on Space Operations Automation and Robotics (SOAR ?E7)*, Houston, TX, August 1987.
Warren, K. C., and Goodman, B. A. ?Engineering Intelligent Tutoring Systems,?EProceedings of The Contributed Sessions 1993 Conference on Intelligent Computer Aided Training and Virtual Environment Technology (ICAT-VET ?E3), Houston, TX, May 1993.
Wiederholt, B. J. ?MITT Writer: An Authoring System for Developing Intelligent Tutors for Complex Technical Domains,?E*Proceedings of Contributed Sessions 1991 Conference on Intelligent Computer Aided Training*, Houston, TX, November 1991.
Woods, D. ?Space Station Freedom: Embedding AI,?E*AI Expert*, April 1992.
Enhancements/Implementation
Donnell, B., ?Object/rule Integration in CLIPS,?E*Expert Systems: The International Journal of Knowledge Engineering and Neural Networks*, Learned Information, New Jersey, February 1994, Vol. 11, No. 1, ISSN 0266-4720, pp. 29-45.
Franke, J. L., et al. ?A General Purpose Certainty Processing Extension to CLIPS,?E*Proceedings of The 7th Florida Artificial Intelligence Research Symposium*, Florida AI Research Society, 1994.
Le, T., and Homeier, P. ?Portable Inference Engine: An Extended CLIPS for Real?Time Production Systems,?E*Proceedings of The Second Annual Workshop on Space Operations Automation and Robotics (SOAR ?E8)*, Albuquerque, NM, July 1988.
Li, Y. P. ?DCLIPS?A Distributed CLIPS Implementation,?E*Proceedings of the 9th AIAA Computing in Aerospace Conference*, American Institute of Aeronautics and Astronautics, San Diego, CA, October 1993.
Odette, L. L., Intelligent Embedded Systems, Addison?Wesley Publishing Company, pp.?63?E10,?1991.
Riley, G. ?Implementing CLIPS on a Parallel Computer,?E*Proceedings of The First Annual Workshop on Space Operations Automation and Robotics (SOAR ?E7)*, Houston, TX, August 1987.
Riley, G. ?Implementation of an Expert System Shell on a Parallel Computer,?E*Proceedings of The Third Annual Artificial Intelligence & Advanced Computer Technology Conference*, Long Beach Convention Center, Long Beach, CA, April 1987.
Salzgeber, M. J., et al. ?Managing Uncertainty in CLIPS: A System Level Approach,?E*Proceedings of The 6th Florida Artificial Intelligence Research Symposium*, Florida AI Research Society, 1993.
Eick, C. F., et al. ?DALI?A Knowledge Base Management System,?E Proceedings of the 1st Conference on Industrial and Engineering Applications of AI & Expert Systems.
Rete Pattern Matching Algorithm
Forgy, C. ?Rete: A Fast Algorithm for the Many Pattern/Many Object Pattern Match Problem,?EArtificial Intelligence, 19, pp. 17?E7, 1982.
Forgy, C. ?On the Efficient Implementation of Production Systems,?EPh. D. Thesis, Carnegie-Mellon University, 1979.
Schneier, B. ?The Rete Matching Algorithm,?E*AI Expert*, pp. 24-29, December 1992.
Index¶
- 190: 44? 7?DERIVE 22?NONE 22?self 109, 110( 7) 7*
190** 197/ 191& 7, 41+ 189< 7, 164<= 165<> 163= 46, 162=> 27> 163>= 164| 7, 41~ 7, 41$? 7abs 192abstraction 18action 16, 27, 159activated 28active-duplicate-instance 83, 115, 130active-initialize-instance 83, 124active-make-instance 83, 121, 123active-message-duplicate-instance 83, 115, 132active-message-modify-instance 83, 115, 129active-modify-instance 83, 114, 128Ada iv, 8, 9, 15, 16Advanced Programming Guide v, 1, 3, 5, 8, 51, 161, 178, 194, 309agenda 28, 29, 33, 62, 289, 290, 291allowed-classes 154allowed-instance-names 155allowed-instances 155ampersand 7and 165antecedent 15any-factp 230, 324any-instancep 83, 139apropos 275arrow 27ART iiiArtificial Intelligence Section iiiassert 11, 22, 83, 211, 217, 220, 266assert-string 220attributedefault 22auto-focus 63backslash 7, 180, 185, 186, 220Basic Programming Guide iv, v, 1batch 3, 5, 272batch* 5, 272bind 39, 65, 83, 110, 126, 199bload 270, 271, 274bload-instances 307, 308break 83, 139, 202, 204, 230browse-classes 302bsave 153, 270, 271bsave-instances 307, 308build 175, 326C iii, 8, 9, 12, 15, 16, 21call-next-handler 83, 117, 118, 255call-next-method 83, 86, 241, 242call-specific-method 75, 83, 86, 242carriage return 7case sensitive 7check-syntax 177class 8, 13, 78, 258, 299, 302abstract 90, 95, 253, 299concrete 91, 95, 253existence 245immediate 95, 107non-reactive 95precedence 93reactive 91, 95, 253specific 92, 95, 100, 118system 89ADDRESS 89EXTERNAL-ADDRESS 89FACT-ADDRESS 89FLOAT 89INITIAL-OBJECT 89INSTANCE 89INSTANCE-ADDRESS 89INSTANCE-NAME 89INTEGER 89LEXEME 89MULTIFIELD 89NUMBER 89OBJECT 89, 92, 302PRIMITIVE 89STRING 89SYMBOL 89USER 89, 92, 112, 124, 257, 306user-defined 8, 14, 306class function 240, 258class-abstractp 247class-existp 245class-reactivep 247class-slots 248class-subclasses 248class-superclasses 247clear 11, 25, 65, 123, 145, 147, 151, 270, 271clear-focus-stack 292CLIPS iiiCLOS 75, 89close 180command 3, 159, 269command prompt 3comment 7, 10Common Lisp Object System ivcondition 16conditional element 16, 25, 27, 33, 62and 27, 33, 53exists 33, 55forall 33, 56logical 33, 58not 33, 54or 33, 52pattern 27, 33, 34literal 35test 30, 33, 51conflict resolution strategy 16, 28, 29, 271, 272, 291breadth 29complexity 30depth 29lex 30mea 31random 32simplicity 29consequent 15conservation 253conserve-mem 270, 310constant 3, 9constraint 33, 34, 41, 44connective 34, 41field 34literal 35predicate 34, 44, 51return value 34, 46construct 3, 10, 175constructs 316constructs-to-c 274, 324, 325convenience 253COOL iv, 8, 14, 17, 18, 19, 75, 78, 89, 240, 244, 298create$ 166crlf 181daemon 111, 121, 137deactivated 28declarative technique 86, 107, 118declare 62default-dynamic 22defclass 8, 10, 91, 105, 298defclass-module 244deffacts 10, 13, 25, 283deffacts-module 234deffunction 9, 10, 16, 71, 75, 294, 295action 72advantages over generic functions 341execution error 72recursion 72regular parameter 71return value 72wildcard parameter 71deffunction-module 238defgeneric 10, 75, 76defgeneric-module 239defglobal 10, 15, 65, 293defglobal-module 238definstances 10, 15, 91, 122, 305initial-object 91definstances-module 256defmessage-handler 10, 105, 106, 303defmethod 10, 75, 76defmodule 10, 145, 308, 309defmodules 17defrule 10, 27, 283defrule-module 235deftemplate 10, 12, 21, 279deftemplate fact 12, 21, 220deftemplate-module 212deftemplate-slot-allowed-values 212, 322deftemplate-slot-cardinality 212, 322deftemplate-slot-defaultp 213, 322deftemplate-slot-default-value 214, 322deftemplate-slot-existp 214, 322deftemplate-slot-multip 215, 322deftemplate-slot-names 215, 322deftemplate-slot-range 216, 322deftemplate-slot-singlep 216, 323deftemplate-slot-type 323deftemplate-slot-types 216deg-grad 195deg-rad 195delayed-do-for-all-facts 230, 233, 324delayed-do-for-all-instances 83, 139, 142, 204, 327delete$ 168delete-instance 126, 257delete-member$ 172delimiter 7dependencies 289dependents 289describe-class 92, 299direct-insert$ 262div 191do-for-all-facts 230, 232, 233, 324do-for-all-instances 83, 139, 141, 142, 204, 327do-for-fact 230, 232, 324do-for-instance 83, 139, 141, 204, 327double quote 7dribble-off 276dribble-on 275duplicate 11, 13, 23, 83, 220, 266duplicate-instance 83, 115, 130dynamic binding 18dynamic-get 125, 260, 371dynamic-put 125, 261, 371embedded application 5encapsulation 18, 89, 109, 120EnvFalseSymbol 325EnvTrueSymbol 325EOF 182, 183, 187eq 161eval 175, 326evenp 160exit 4, 180, 271exp 197expand$ 83, 108, 266, 325explode$ 168exponential notation 6exporting constructs 147expression 10external-address 6, 8, 9, 181-f 4-f2 5facet 91, 96, 299accessinitialize-only 98read-only 98read-write 98create-accessor 103, 253, 326?NONE 103read 103read-write 103write 103default 96default-dynamic 96multislot 96override-message 104pattern-matchnon-reactive 101reactive 101propagationinherit 99no-inherit 95, 99shared 96single-slot 96slot 96sourcecomposite 95, 100exclusive 100storagelocal 97shared 97visibility 102private 102public 102fact 11, 13, 25, 280fact identifier 11fact-address 6, 8, 9, 11, 50, 181, 227fact-existp 222fact-index 11, 23, 218, 219, 220, 221, 289fact-list 11, 13, 25, 27fact-relation 222facts 280fact-set 226action 229distributed action 229member 226member variable 226, 229query 228, 229query execution error 230query functions 230template 226template restriction 226fact-slot-names 222fact-slot-value 223FALSE 44FalseSymbol 325fetch 312, 324ff 181field 9, 12find-all-facts 231, 233, 324find-all-instances 83, 140, 142find-fact 231, 324find-instance 83, 140fire 27first$ 171float 6, 8, 193floatp 159focus 28, 63, 151, 291foreach 83, 204, 206, 266, 322format 183, 188, 323FORTRAN 9funcall 211, 324, 325, 327function 3, 9, 16, 75, 138, 159, 229call 3, 10external 5, 39, 46, 51predicate 44, 51, 159, 259reserved names 393system defined 9, 393user defined 8, 9, 51, 378generic dispatch 75, 76, 79, 81, 341generic function 14, 16, 17, 75, 295disadvantages 341header 76, 77order dependence 76ordering of method parameter restrictions 341performance penalty 76return value 87gensym 207, 208gensym* 121, 129, 207, 208get-auto-float-dividend 274get-char 186, 323get-class-defaults-mode 253, 327get-current-module 263get-defclass-list 244get-deffacts-list 234get-deffunction-list 238get-defgeneric-list 239get-defglobal-list 237GetDefglobalValue 325get-definstances-list 256get-defmessage-handler-list 248get-defmethod-list 239get-defmodule-list 263get-defrule-list 235get-deftemplate-list 217get-dynamic-constraint-checking 274get-fact-duplication 282get-fact-list 224get-focus 236get-focus-stack 236get-function-restrictions 83, 210get-incremental-reset 288get-method-restrictions 83, 243GetNextFactInTemplate 324get-profile-percent-threshold 315get-region 314, 323get-reset-globals 294get-salience-evaluation 292get-sequence-operator-recognition 267get-static-constraint-checking 275get-strategy 291grad-deg 195halt 291help 322help-path 322I/O router 178if 83, 200, 266if portion 15imperative technique 86, 107, 118implode$ 169importing constructs 147incremental reset 28, 272, 288Inference Corporation iiiinference engine 16, 27, 28inheritance 14, 18, 91, 95class precedence list 19, 91, 92, 93, 95, 100, 118, 299class precedence list 106is-a 92multiple 14, 19, 89, 92, 93, 302initialize-instance 83, 97, 104, 112, 124, 257init-slots 112, 121, 124, 257insert$ 170instance 8, 13, 14, 15, 95, 97, 299, 306active 109, 116, 118, 125, 126, 257, 260, 306creation 116, 120deletion 113direct 90, 91, 95, 99initialization 112, 120, 124, 257manipulation 120printing 113instance-address 6, 8, 9, 50, 181, 258, 259, 341instance-addressp 260instance-existp 260instance-list 15, 27instance-name 6, 8, 135, 258, 259, 260instance-namep 260instance-name-to-symbol 259instancep 259instances 306instance-set 135action 138class restriction 135distributed action 137member 135member variable 135, 138query 19, 137, 138, 341query execution error 139query functions 139template 135integer 6, 8, 193integerp 159integration 5Interfaces Guide v, 3Jess 207-l 5left-hand side 15length 209length$ 96, 108, 172, 209less than 7lexemep 160LHS 27line feed 7LISP iii, 15list-defclasses 298list-deffacts 283list-deffunctions 295list-defgenerics 296list-defglobals 293list-definstances 305list-defmessage-handlers 303list-defmethods 77, 83, 84, 296, 297list-defmodules 309list-defrules 284list-deftemplates 279list-focus-stack 292list-watch-items 278load 5, 269, 270, 272load* 269load-facts 280LoadFactsFromString 326load-instances 308local 281log 197log10 198logical name 179, 275nil 181, 183stdin 182, 183, 186, 187, 275stdout 181, 183, 275t 181, 182, 183, 186, 187wclips 275wdialog 275wdisplay 275werror 275wtrace 275wwarning 275logical support 58, 218, 219, 289loop-for-count 83, 202, 204, 266lowcase 176make-instance 8, 48, 83, 95, 97, 99, 104, 112, 120, 122, 257, 308matches 285math functions 189, 194max 192max-number-of-elements 156member$ 167, 326mem-requests 309mem-used 309message 14, 16, 17, 18, 19, 75, 89, 97, 106, 108, 109, 116, 118, 120, 121, 124dispatch 107execution error 108, 118, 254execution error 119implementation 106, 107return value 120message dispatch 116message-duplicate-instance 83, 104, 115, 131message-handler 14, 16, 17, 19, 76, 89, 91, 92, 99, 106, 109, 118, 120, 125, 199, 257, 299, 306, 341action 109applicability 107, 108, 116, 118, 304documentation 105existence 246forward declaration 105regular parameter 108return value 120shadow 118, 254specific 116, 118, 120systemcreate 116, 120, 121, 326delete 113, 121, 122, 126, 129direct-duplicate 115, 130direct-modify 114, 127, 128init 99, 112, 120, 121, 124, 256message-duplicate 115, 131, 132message-modify 115, 128, 129print 113typeafter 106, 118, 120around 106, 118, 120, 254before 106, 118, 120primary 106, 118, 120wildcard parameter 108message-handler-existp 246message-modify-instance 83, 104, 115, 128method 17, 75, 76, 89action 76applicability 79, 86, 297execution error 86, 240explicit 75, 79, 82implicit 75, 76, 79index 77, 296parameter query restriction 78parameter restriction 76, 77, 78, 82, 84parameter type restriction 78precedence 78, 79, 84, 296regular parameter 78, 79return value 87shadow 86, 240, 304wildcard parameter 79wildcard parameter restriction 76min 192min-number-of-elements 156mod 198modify 11, 13, 23, 83, 219, 266modify-instance 83, 114, 127module specifier 147multifield value 8, 9multifield wildcard 36multifieldp 161named fields 12NASA iiineq 162next-handlerp 83, 254next-methodp 83, 240non-FALSE 44non-ordered fact 12, 21not 166nth$ 96, 166numberp 159object 8, 13, 17, 18behavior 13, 16, 17, 18, 75, 91, 106, 107primitive type 14properties 13, 14, 17, 18, 91reference 8, 13, 19object-pattern-match-delay 48, 83, 126, 266oddp 161off 316open 179, 180operating-system 211, 322OPS5 30options 273or 165ordered fact 12, 21overload 10, 17, 71, 75, 76, 341override-next-handler 83, 117, 118, 255override-next-method 83, 86, 241, 242parenthesis 7, 10Pascal 12, 16, 21pattern 16, 27pattern entity 27pattern-address 50pattern-matching 16, 65, 66performance 339pi 196pointerp 161polymorphism 18pop-focus 237ppdefclass 298ppdeffacts 283ppdeffunction 295ppdefgeneric 295ppdefglobal 293ppdefinstances 305ppdefmessage-handler 303ppdefmethod 296ppdefmodule 309ppdefrule 147, 271, 284ppdeftemplate 279ppfact 282, 323ppinstance 306pprule 284prefix notation 10preview-generic 297preview-send 304printout 181, 183, 327print-region 313profile 316profile-info 315, 316profile-reset 315progn 83, 126, 138, 203, 204, 266, 316, 327progn$ 83, 203, 204, 207, 266, 326quote 7rad-deg 196random 208, 327read 178, 182, 183, 272readline 182, 272read-number 187, 188, 323Reference Manual v, viirefresh 288refresh-agenda 292release-mem 310remove 186remove-break 287rename 185replace$ 170replace-member$ 172reset 11, 13, 15, 25, 65, 91, 120, 122, 151, 159, 271, 272, 283, 294rest$ 171restore-instances 308RETE algorithm 339retract 11, 50, 218return 28, 83, 139, 151, 202, 204, 230, 266RHS 27right-hand side 15round 198roundoff 6RtnArgCount 326rule 15, 27run 151, 290, 291salience 28, 29, 62, 292dynamic 28, 63, 292save 270, 310, 326save-facts 281save-instances 307, 308scientific math functions 194seed 33, 209semicolon 7, 10send 17, 19, 106, 116, 119, 120, 304, 341sequence expansion 39sequencep 161set-auto-float-dividend 191, 274set-break 287set-class-defaults-mode 253, 326, 327set-current-module 147, 263, 290set-dynamic-constraint-checking 23, 105, 153, 271, 274set-fact-duplication 281setgen 208set-incremental-reset 288set-locale 187, 188, 323set-profile-percent-threshold 315set-reset-globals 65, 294set-salience-evaluation 63, 292set-sequence-operator-recognition 267set-static-constraint-checking 23, 105, 153, 274set-strategy 29, 159, 291show-breaks 288show-defglobals 294significant digits 6single-field value 9single-field wildcard 36slot 12, 14, 19, 91, 92, 95, 100, 120, 245, 299access 98, 103, 245, 246accessor 103, 137put-<slot-name> 121default value 96, 97, 121, 124, 257, 307direct access 110, 125, 137, 199existence 245facet 96, 100inheritance propagation 99multifield 261overlay 100override 99visibility 246slot daemons 341slot-allowed-classes 254, 323slot-allowed-values 251slot-cardinality 251slot-default-value 252slot-delete$ 262slot-direct-accessp 246slot-direct-delete$ 262slot-direct-replace$ 261slot-existp 245slot-facets 249slot-initablep 246slot-insert$ 96, 262slot-override 121, 124, 257, 307slot-publicp 246slot-range 252slot-replace$ 261slot-sources 250slot-types 250slot-writablep 246, 325Smalltalk iv, 75, 89sort 210, 327space 7specificity 29sqrt 196standard math functions 189str-cat 173str-compare 176str-index 174string 6, 7, 8stringp 160string-to-field 178, 327str-length 177subclass 92, 116, 245, 299, 302subclassp 245subseq$ 169subsetp 167sub-string 174superclass 91, 92, 95, 106, 245, 299direct 92superclassp 245switch 83, 205, 266, 327symbol 6, 7, 8, 258, 259reserved 12and 12declare 12exists 12forall 12logical 12not 12object 12or 12test 12symbolp 160symbol-to-instance-name 259sym-cat 173system 273tab 7, 181template 219then portion 15tilde 7time 209timer 211timer 327top level 3toss 315trigonometric math functions 194TrueSymbol 325truth maintenance 58type function 240, 258unconditional support 58undefclass 298undeffacts 283undeffunction 295undefgeneric 296undefglobal 65, 293undefinstances 306undefmessage-handler 304undefmethod 297undefrule 147, 284undeftemplate 279unmake-instance 50, 257unwatch 278upcase 176User?s Guide v, viiuser-functions 316value 9variable 5, 7, 9, 11, 15, 34, 35, 38, 54, 175, 199global 3, 15, 62, 65, 199, 271vertical bar 7visible 281vtab 181watch 276, 278watch itemactivations 28, 277all 277compilations 269, 276deffunctions 277facts 217, 218, 276focus 277generic-functions 277globals 65, 277instances 277message-handlers 277messages 277methods 277rules 277, 290slots 277statistics 277, 290while 83, 201, 266wildcard 34, 35, 36wordp 160