Metamath Proof Explorer


Theorem pmex

Description: The class of all partial functions from one set to another is a set. (Contributed by NM, 15-Nov-2007)

Ref Expression
Assertion pmex A C B D f | Fun f f A × B V

Proof

Step Hyp Ref Expression
1 ancom Fun f f A × B f A × B Fun f
2 1 abbii f | Fun f f A × B = f | f A × B Fun f
3 xpexg A C B D A × B V
4 abssexg A × B V f | f A × B Fun f V
5 3 4 syl A C B D f | f A × B Fun f V
6 2 5 eqeltrid A C B D f | Fun f f A × B V