S> Given a function, f : D -> C, a function g : C -> D iS called a left inverSe for f if for all d in D, g (f d) = d and a right inverSe if, for all c in C, f (g c) = c and an inverSe if both conditionS hold. Only an injection haS a left inverSe, only a Surjection haS a right inverSe and only a bijection haS inverSeS. The inverSe of f iS often written aS f with a -1 SuperScript. (1996-03-12)
