Metamath Proof Explorer


Theorem dvelimc

Description: Version of dvelim for classes. Usage of this theorem is discouraged because it depends on ax-13 . (Contributed by Mario Carneiro, 8-Oct-2016) (New usage is discouraged.)

Ref Expression
Hypotheses dvelimc.1
|- F/_ x A
dvelimc.2
|- F/_ z B
dvelimc.3
|- ( z = y -> A = B )
Assertion dvelimc
|- ( -. A. x x = y -> F/_ x B )

Proof

Step Hyp Ref Expression
1 dvelimc.1
 |-  F/_ x A
2 dvelimc.2
 |-  F/_ z B
3 dvelimc.3
 |-  ( z = y -> A = B )
4 nftru
 |-  F/ x T.
5 nftru
 |-  F/ z T.
6 1 a1i
 |-  ( T. -> F/_ x A )
7 2 a1i
 |-  ( T. -> F/_ z B )
8 3 a1i
 |-  ( T. -> ( z = y -> A = B ) )
9 4 5 6 7 8 dvelimdc
 |-  ( T. -> ( -. A. x x = y -> F/_ x B ) )
10 9 mptru
 |-  ( -. A. x x = y -> F/_ x B )