Metamath Proof Explorer


Theorem elpm2r

Description: Sufficient condition for being a partial function. (Contributed by NM, 31-Dec-2013)

Ref Expression
Assertion elpm2r A V B W F : C A C B F A 𝑝𝑚 B

Proof

Step Hyp Ref Expression
1 fdm F : C A dom F = C
2 1 feq2d F : C A F : dom F A F : C A
3 1 sseq1d F : C A dom F B C B
4 2 3 anbi12d F : C A F : dom F A dom F B F : C A C B
5 4 adantr F : C A C B F : dom F A dom F B F : C A C B
6 5 ibir F : C A C B F : dom F A dom F B
7 elpm2g A V B W F A 𝑝𝑚 B F : dom F A dom F B
8 6 7 syl5ibr A V B W F : C A C B F A 𝑝𝑚 B
9 8 imp A V B W F : C A C B F A 𝑝𝑚 B