Metamath Proof Explorer


Theorem acnlem

Description: Construct a mapping satisfying the consequent of isacn . (Contributed by Mario Carneiro, 31-Aug-2015)

Ref Expression
Assertion acnlem A V x A B f x g x A g x f x

Proof

Step Hyp Ref Expression
1 fvssunirn f x ran f
2 simpr x A B f x B f x
3 1 2 sseldi x A B f x B ran f
4 3 ralimiaa x A B f x x A B ran f
5 eqid x A B = x A B
6 5 fmpt x A B ran f x A B : A ran f
7 4 6 sylib x A B f x x A B : A ran f
8 id A V A V
9 vex f V
10 9 rnex ran f V
11 10 uniex ran f V
12 fex2 x A B : A ran f A V ran f V x A B V
13 11 12 mp3an3 x A B : A ran f A V x A B V
14 7 8 13 syl2anr A V x A B f x x A B V
15 5 fvmpt2 x A B f x x A B x = B
16 15 2 eqeltrd x A B f x x A B x f x
17 16 ralimiaa x A B f x x A x A B x f x
18 17 adantl A V x A B f x x A x A B x f x
19 nfmpt1 _ x x A B
20 19 nfeq2 x g = x A B
21 fveq1 g = x A B g x = x A B x
22 21 eleq1d g = x A B g x f x x A B x f x
23 20 22 ralbid g = x A B x A g x f x x A x A B x f x
24 14 18 23 spcedv A V x A B f x g x A g x f x