FullyRetractableTo(S)

retract.spad line 1 [edit on github]

• S : Type

A is fully retractable to B means that A is retractable to B, and, in addition, if B is retractable to the integers or rational numbers then so is A. In particular, what we are asserting is that there are no integers (rationals) in A which don't retract into B. Date Created: March 1990

coerce : S -> %

from CoercibleFrom(S)

coerce : Fraction(Integer) -> % if S has RetractableTo(Fraction(Integer))

from CoercibleFrom(Fraction(Integer))

coerce : Integer -> % if S has RetractableTo(Integer)

from CoercibleFrom(Integer)

retract : % -> S

from RetractableTo(S)

retract : % -> Fraction(Integer) if S has RetractableTo(Fraction(Integer))

from RetractableTo(Fraction(Integer))

retract : % -> Integer if S has RetractableTo(Integer)

from RetractableTo(Integer)

retractIfCan : % -> Union(S, "failed")

from RetractableTo(S)

retractIfCan : % -> Union(Fraction(Integer), "failed") if S has RetractableTo(Fraction(Integer))

from RetractableTo(Fraction(Integer))

retractIfCan : % -> Union(Integer, "failed") if S has RetractableTo(Integer)

from RetractableTo(Integer)

RetractableTo(S)

RetractableTo(Integer)

RetractableTo(Fraction(Integer))

CoercibleFrom(Integer)

CoercibleFrom(Fraction(Integer))

CoercibleFrom(S)