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 ) ) | 
| 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 ) ) |