Metamath Proof Explorer


Theorem cusgrexilem1

Description: Lemma 1 for cusgrexi . (Contributed by Alexander van der Vekens, 12-Jan-2018)

Ref Expression
Hypothesis usgrexi.p P = x 𝒫 V | x = 2
Assertion cusgrexilem1 V W I P V

Proof

Step Hyp Ref Expression
1 usgrexi.p P = x 𝒫 V | x = 2
2 pwexg V W 𝒫 V V
3 1 2 rabexd V W P V
4 resiexg P V I P V
5 3 4 syl V W I P V