Metamath Proof Explorer


Theorem vtocl4ga

Description: Implicit substitution of 4 classes for 4 setvar variables. (Contributed by AV, 22-Jan-2019)

Ref Expression
Hypotheses vtocl4ga.1 x = A φ ψ
vtocl4ga.2 y = B ψ χ
vtocl4ga.3 z = C χ ρ
vtocl4ga.4 w = D ρ θ
vtocl4ga.5 x Q y R z S w T φ
Assertion vtocl4ga A Q B R C S D T θ

Proof

Step Hyp Ref Expression
1 vtocl4ga.1 x = A φ ψ
2 vtocl4ga.2 y = B ψ χ
3 vtocl4ga.3 z = C χ ρ
4 vtocl4ga.4 w = D ρ θ
5 vtocl4ga.5 x Q y R z S w T φ
6 eleq1 x = A x Q A Q
7 6 anbi1d x = A x Q y R A Q y R
8 7 anbi1d x = A x Q y R z S w T A Q y R z S w T
9 8 1 imbi12d x = A x Q y R z S w T φ A Q y R z S w T ψ
10 eleq1 y = B y R B R
11 10 anbi2d y = B A Q y R A Q B R
12 11 anbi1d y = B A Q y R z S w T A Q B R z S w T
13 12 2 imbi12d y = B A Q y R z S w T ψ A Q B R z S w T χ
14 eleq1 z = C z S C S
15 14 anbi1d z = C z S w T C S w T
16 15 anbi2d z = C A Q B R z S w T A Q B R C S w T
17 16 3 imbi12d z = C A Q B R z S w T χ A Q B R C S w T ρ
18 eleq1 w = D w T D T
19 18 anbi2d w = D C S w T C S D T
20 19 anbi2d w = D A Q B R C S w T A Q B R C S D T
21 20 4 imbi12d w = D A Q B R C S w T ρ A Q B R C S D T θ
22 9 13 17 21 5 vtocl4g A Q B R C S D T A Q B R C S D T θ
23 22 pm2.43i A Q B R C S D T θ