Also converse is true:
- For each a*b, left hand side of
only one equation "matches":
- Either b = 0 or b = y' for some y.
- Consequence of first Peano axiom.
- Equality b = y' determines unique y.
- (b = y0' /\ b = y1') => y0 = y1 for all y0 and y1.
- Consequence of second Peano axiom.
Pair of equations uniquely determines a function.
Author: Wolfgang Schreiner
Last Modification: November 24, 1999