Metamath Proof Explorer


Theorem isomuspgrlem2

Description: Lemma 2 for isomuspgr . (Contributed by AV, 1-Dec-2022)

Ref Expression
Hypotheses isomushgr.v V = Vtx A
isomushgr.w W = Vtx B
isomushgr.e E = Edg A
isomushgr.k K = Edg B
Assertion isomuspgrlem2 A USHGraph B USHGraph f : V 1-1 onto W a V b V a b E f a f b K g g : E 1-1 onto K e E f e = g e

Proof

Step Hyp Ref Expression
1 isomushgr.v V = Vtx A
2 isomushgr.w W = Vtx B
3 isomushgr.e E = Edg A
4 isomushgr.k K = Edg B
5 3 fvexi E V
6 5 mptex x E f x V
7 eqid x E f x = x E f x
8 simplll A USHGraph B USHGraph f : V 1-1 onto W a V b V a b E f a f b K A USHGraph
9 simplr A USHGraph B USHGraph f : V 1-1 onto W a V b V a b E f a f b K f : V 1-1 onto W
10 simpr A USHGraph B USHGraph f : V 1-1 onto W a V b V a b E f a f b K a V b V a b E f a f b K
11 vex f V
12 11 a1i A USHGraph B USHGraph f : V 1-1 onto W a V b V a b E f a f b K f V
13 simpllr A USHGraph B USHGraph f : V 1-1 onto W a V b V a b E f a f b K B USHGraph
14 1 2 3 4 7 8 9 10 12 13 isomuspgrlem2e A USHGraph B USHGraph f : V 1-1 onto W a V b V a b E f a f b K x E f x : E 1-1 onto K
15 1 2 3 4 7 isomuspgrlem2a f V e E f e = x E f x e
16 11 15 mp1i A USHGraph B USHGraph f : V 1-1 onto W a V b V a b E f a f b K e E f e = x E f x e
17 14 16 jca A USHGraph B USHGraph f : V 1-1 onto W a V b V a b E f a f b K x E f x : E 1-1 onto K e E f e = x E f x e
18 f1oeq1 g = x E f x g : E 1-1 onto K x E f x : E 1-1 onto K
19 fveq1 g = x E f x g e = x E f x e
20 19 eqeq2d g = x E f x f e = g e f e = x E f x e
21 20 ralbidv g = x E f x e E f e = g e e E f e = x E f x e
22 18 21 anbi12d g = x E f x g : E 1-1 onto K e E f e = g e x E f x : E 1-1 onto K e E f e = x E f x e
23 22 spcegv x E f x V x E f x : E 1-1 onto K e E f e = x E f x e g g : E 1-1 onto K e E f e = g e
24 6 17 23 mpsyl A USHGraph B USHGraph f : V 1-1 onto W a V b V a b E f a f b K g g : E 1-1 onto K e E f e = g e
25 24 ex A USHGraph B USHGraph f : V 1-1 onto W a V b V a b E f a f b K g g : E 1-1 onto K e E f e = g e