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=x𝒫V|x=2
Assertion cusgrexilem1 VWIPV

Proof

Step Hyp Ref Expression
1 usgrexi.p P=x𝒫V|x=2
2 pwexg VW𝒫VV
3 1 2 rabexd VWPV
4 resiexg PVIPV
5 3 4 syl VWIPV