Metamath Proof Explorer


Theorem mpteq12dv

Description: An equality inference for the maps-to notation. (Contributed by NM, 24-Aug-2011) (Revised by Mario Carneiro, 16-Dec-2013) Remove dependency on ax-10 , ax-12 . (Revised by SN and Gino Giotto, 1-Dec-2023)

Ref Expression
Hypotheses mpteq12dv.1
|- ( ph -> A = C )
mpteq12dv.2
|- ( ph -> B = D )
Assertion mpteq12dv
|- ( ph -> ( x e. A |-> B ) = ( x e. C |-> D ) )

Proof

Step Hyp Ref Expression
1 mpteq12dv.1
 |-  ( ph -> A = C )
2 mpteq12dv.2
 |-  ( ph -> B = D )
3 2 adantr
 |-  ( ( ph /\ x e. A ) -> B = D )
4 1 3 mpteq12dva
 |-  ( ph -> ( x e. A |-> B ) = ( x e. C |-> D ) )