Metamath Proof Explorer


Theorem csbied2

Description: Conversion of implicit substitution to explicit class substitution, deduction form. (Contributed by Mario Carneiro, 2-Jan-2017)

Ref Expression
Hypotheses csbied2.1
|- ( ph -> A e. V )
csbied2.2
|- ( ph -> A = B )
csbied2.3
|- ( ( ph /\ x = B ) -> C = D )
Assertion csbied2
|- ( ph -> [_ A / x ]_ C = D )

Proof

Step Hyp Ref Expression
1 csbied2.1
 |-  ( ph -> A e. V )
2 csbied2.2
 |-  ( ph -> A = B )
3 csbied2.3
 |-  ( ( ph /\ x = B ) -> C = D )
4 id
 |-  ( x = A -> x = A )
5 4 2 sylan9eqr
 |-  ( ( ph /\ x = A ) -> x = B )
6 5 3 syldan
 |-  ( ( ph /\ x = A ) -> C = D )
7 1 6 csbied
 |-  ( ph -> [_ A / x ]_ C = D )