seg.spad line 1 [edit on github]
This category provides operations on ranges, or segments as they are called.
(l..h) returns segment +il+i .. h+i.
i+(l..h) returns segment i+l .. i+h.
(l..h) returns segment -il-i .. h-i.
s by n creates a new segment in which only every n-th element is used.
l..h creates a segment with l and h as the endpoints.
convert(i) creates the segment i..i.
high(s) returns the second endpoint of s. Note: high(l..h) = h.
incr(s) returns n, where s is a segment in which every n-th element is used. Note: incr(l..h by n) = n.
low(s) returns the first endpoint of s. Note: low(l..h) = l.
reverse(s) returns segment s in reverse order.
segment(i, j) is an alternate way to create the segment i..j.