Metamath Proof Explorer


Theorem ixpconstg

Description: Infinite Cartesian product of a constant B . (Contributed by Mario Carneiro, 11-Jan-2015)

Ref Expression
Assertion ixpconstg
|- ( ( A e. V /\ B e. W ) -> X_ x e. A B = ( B ^m A ) )

Proof

Step Hyp Ref Expression
1 vex
 |-  f e. _V
2 1 elixpconst
 |-  ( f e. X_ x e. A B <-> f : A --> B )
3 2 abbi2i
 |-  X_ x e. A B = { f | f : A --> B }
4 mapvalg
 |-  ( ( B e. W /\ A e. V ) -> ( B ^m A ) = { f | f : A --> B } )
5 3 4 eqtr4id
 |-  ( ( B e. W /\ A e. V ) -> X_ x e. A B = ( B ^m A ) )
6 5 ancoms
 |-  ( ( A e. V /\ B e. W ) -> X_ x e. A B = ( B ^m A ) )