FullyRetractableTo SΒΆ

retract.spad line 1

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

RetractableTo Fraction Integer if S has RetractableTo Fraction Integer

RetractableTo Integer if S has RetractableTo Integer

RetractableTo S