Metamath Proof Explorer


Theorem wl-ax11-lem6

Description: Lemma. (Contributed by Wolf Lammen, 30-Jun-2019)

Ref Expression
Assertion wl-ax11-lem6 uu=y¬xx=yuxuyφxyφ

Proof

Step Hyp Ref Expression
1 ax-wl-11v uxuyφxuuyφ
2 ax-wl-11v xuuyφuxuyφ
3 1 2 impbii uxuyφxuuyφ
4 nfna1 x¬xx=y
5 wl-ax11-lem3 ¬xx=yxuu=y
6 4 5 nfan1 x¬xx=yuu=y
7 wl-ax11-lem5 uu=yuuyφyφ
8 7 adantl ¬xx=yuu=yuuyφyφ
9 6 8 albid ¬xx=yuu=yxuuyφxyφ
10 9 ancoms uu=y¬xx=yxuuyφxyφ
11 3 10 bitrid uu=y¬xx=yuxuyφxyφ