Metamath Proof Explorer


Theorem finxpsuc

Description: The value of Cartesian exponentiation at a successor. (Contributed by ML, 24-Oct-2020)

Ref Expression
Assertion finxpsuc
|- ( ( N e. _om /\ N =/= (/) ) -> ( U ^^ suc N ) = ( ( U ^^ N ) X. U ) )

Proof

Step Hyp Ref Expression
1 nnord
 |-  ( N e. _om -> Ord N )
2 ordge1n0
 |-  ( Ord N -> ( 1o C_ N <-> N =/= (/) ) )
3 1 2 syl
 |-  ( N e. _om -> ( 1o C_ N <-> N =/= (/) ) )
4 3 biimprd
 |-  ( N e. _om -> ( N =/= (/) -> 1o C_ N ) )
5 4 imdistani
 |-  ( ( N e. _om /\ N =/= (/) ) -> ( N e. _om /\ 1o C_ N ) )
6 eqid
 |-  ( y e. _om , x e. _V |-> if ( ( y = 1o /\ x e. U ) , (/) , if ( x e. ( _V X. U ) , <. U. y , ( 1st ` x ) >. , <. y , x >. ) ) ) = ( y e. _om , x e. _V |-> if ( ( y = 1o /\ x e. U ) , (/) , if ( x e. ( _V X. U ) , <. U. y , ( 1st ` x ) >. , <. y , x >. ) ) )
7 6 finxpsuclem
 |-  ( ( N e. _om /\ 1o C_ N ) -> ( U ^^ suc N ) = ( ( U ^^ N ) X. U ) )
8 5 7 syl
 |-  ( ( N e. _om /\ N =/= (/) ) -> ( U ^^ suc N ) = ( ( U ^^ N ) X. U ) )