Basic Idea
- A unary function f defines a binary relation (the
function graph):
S := {<x, y>: y = f(x)}.
- A binary relation S defines a function, if the first component of
every tuple in S is unique:
f(x) := such y: <x, y> in S.
We may interpret a special binary relation as a unary function.
Author: Wolfgang Schreiner
Last Modification: October 14, 1999