Metamath Proof Explorer


Theorem shftfib

Description: Value of a fiber of the relation F . (Contributed by Mario Carneiro, 4-Nov-2013)

Ref Expression
Hypothesis shftfval.1 F V
Assertion shftfib A B F shift A B = F B A

Proof

Step Hyp Ref Expression
1 shftfval.1 F V
2 1 shftfval A F shift A = x y | x x A F y
3 2 breqd A B F shift A z B x y | x x A F y z
4 eleq1 x = B x B
5 oveq1 x = B x A = B A
6 5 breq1d x = B x A F y B A F y
7 4 6 anbi12d x = B x x A F y B B A F y
8 breq2 y = z B A F y B A F z
9 8 anbi2d y = z B B A F y B B A F z
10 eqid x y | x x A F y = x y | x x A F y
11 7 9 10 brabg B z V B x y | x x A F y z B B A F z
12 11 elvd B B x y | x x A F y z B B A F z
13 3 12 sylan9bb A B B F shift A z B B A F z
14 ibar B B A F z B B A F z
15 14 adantl A B B A F z B B A F z
16 13 15 bitr4d A B B F shift A z B A F z
17 16 abbidv A B z | B F shift A z = z | B A F z
18 imasng B F shift A B = z | B F shift A z
19 18 adantl A B F shift A B = z | B F shift A z
20 ovex B A V
21 imasng B A V F B A = z | B A F z
22 20 21 mp1i A B F B A = z | B A F z
23 17 19 22 3eqtr4d A B F shift A B = F B A