Example
The following binary relations are functions:
- 0;
- {<0, 0>, <1, 0>, <2, 1>, <3, 2>};
- {<x, x^2>: x in N};
- {<x, x2>: x in N /\ x
is even} union {<x, 0>: x in N /\ x
is odd};
- {<x, y>: x in N /\ y in N /\ x+y = 100};
- {<<x, y>, x+y>: x
in N /\ y in N}.
Check unicity of first tuple component.
Author: Wolfgang Schreiner
Last Modification: October 14, 1999