Metamath Proof Explorer


Theorem wl-ax11-lem3

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

Ref Expression
Assertion wl-ax11-lem3 ¬xx=yxuu=y

Proof

Step Hyp Ref Expression
1 nfna1 x¬xx=y
2 naev ¬xx=y¬uu=x
3 nfa1 uuu=y
4 nfna1 u¬uu=x
5 3 4 nfan uuu=y¬uu=x
6 axc11n xx=yyy=x
7 wl-aetr yy=uyy=xuu=x
8 6 7 syl5 yy=uxx=yuu=x
9 8 aecoms uu=yxx=yuu=x
10 9 con3d uu=y¬uu=x¬xx=y
11 10 imdistani uu=y¬uu=xuu=y¬xx=y
12 wl-ax11-lem2 uu=y¬xx=yxu=y
13 11 12 syl uu=y¬uu=xxu=y
14 5 13 alrimi uu=y¬uu=xuxu=y
15 2 14 sylan2 uu=y¬xx=yuxu=y
16 15 expcom ¬xx=yuu=yuxu=y
17 ax-wl-11v uxu=yxuu=y
18 16 17 syl6 ¬xx=yuu=yxuu=y
19 1 18 nf5d ¬xx=yxuu=y