Metamath Proof Explorer


Theorem uspgrbisymrelALT

Description: Alternate proof of uspgrbisymrel not using the definition of equinumerosity. (Contributed by AV, 26-Nov-2021) (New usage is discouraged.) (Proof modification is discouraged.)

Ref Expression
Hypotheses uspgrbisymrel.g G = v e | v = V q USHGraph Vtx q = v Edg q = e
uspgrbisymrel.r R = r 𝒫 V × V | x V y V x r y y r x
Assertion uspgrbisymrelALT V W f f : G 1-1 onto R

Proof

Step Hyp Ref Expression
1 uspgrbisymrel.g G = v e | v = V q USHGraph Vtx q = v Edg q = e
2 uspgrbisymrel.r R = r 𝒫 V × V | x V y V x r y y r x
3 fvex Pairs V V
4 3 pwex 𝒫 Pairs V V
5 mptexg 𝒫 Pairs V V p 𝒫 Pairs V x y | c p c = x y V
6 4 5 mp1i V W p 𝒫 Pairs V x y | c p c = x y V
7 eqid 𝒫 Pairs V = 𝒫 Pairs V
8 7 1 uspgrex V W G V
9 mptexg G V g G 2 nd g V
10 8 9 syl V W g G 2 nd g V
11 coexg p 𝒫 Pairs V x y | c p c = x y V g G 2 nd g V p 𝒫 Pairs V x y | c p c = x y g G 2 nd g V
12 6 10 11 syl2anc V W p 𝒫 Pairs V x y | c p c = x y g G 2 nd g V
13 eqid p 𝒫 Pairs V x y | c p c = x y = p 𝒫 Pairs V x y | c p c = x y
14 7 2 13 sprsymrelf1o V W p 𝒫 Pairs V x y | c p c = x y : 𝒫 Pairs V 1-1 onto R
15 eqid g G 2 nd g = g G 2 nd g
16 7 1 15 uspgrsprf1o V W g G 2 nd g : G 1-1 onto 𝒫 Pairs V
17 f1oco p 𝒫 Pairs V x y | c p c = x y : 𝒫 Pairs V 1-1 onto R g G 2 nd g : G 1-1 onto 𝒫 Pairs V p 𝒫 Pairs V x y | c p c = x y g G 2 nd g : G 1-1 onto R
18 14 16 17 syl2anc V W p 𝒫 Pairs V x y | c p c = x y g G 2 nd g : G 1-1 onto R
19 f1oeq1 f = p 𝒫 Pairs V x y | c p c = x y g G 2 nd g f : G 1-1 onto R p 𝒫 Pairs V x y | c p c = x y g G 2 nd g : G 1-1 onto R
20 19 spcegv p 𝒫 Pairs V x y | c p c = x y g G 2 nd g V p 𝒫 Pairs V x y | c p c = x y g G 2 nd g : G 1-1 onto R f f : G 1-1 onto R
21 12 18 20 sylc V W f f : G 1-1 onto R