Metamath Proof Explorer


Theorem cureq

Description: Equality theorem for currying. (Contributed by Brendan Leahy, 2-Jun-2021)

Ref Expression
Assertion cureq
|- ( A = B -> curry A = curry B )

Proof

Step Hyp Ref Expression
1 dmeq
 |-  ( A = B -> dom A = dom B )
2 1 dmeqd
 |-  ( A = B -> dom dom A = dom dom B )
3 breq
 |-  ( A = B -> ( <. x , y >. A z <-> <. x , y >. B z ) )
4 3 opabbidv
 |-  ( A = B -> { <. y , z >. | <. x , y >. A z } = { <. y , z >. | <. x , y >. B z } )
5 2 4 mpteq12dv
 |-  ( A = B -> ( x e. dom dom A |-> { <. y , z >. | <. x , y >. A z } ) = ( x e. dom dom B |-> { <. y , z >. | <. x , y >. B z } ) )
6 df-cur
 |-  curry A = ( x e. dom dom A |-> { <. y , z >. | <. x , y >. A z } )
7 df-cur
 |-  curry B = ( x e. dom dom B |-> { <. y , z >. | <. x , y >. B z } )
8 5 6 7 3eqtr4g
 |-  ( A = B -> curry A = curry B )