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Description: Lemma for rpnnen2 . (Contributed by Mario Carneiro, 13-May-2013)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | rpnnen2.1 | |- F = ( x e. ~P NN |-> ( n e. NN |-> if ( n e. x , ( ( 1 / 3 ) ^ n ) , 0 ) ) ) |
|
| Assertion | rpnnen2lem1 | |- ( ( A C_ NN /\ N e. NN ) -> ( ( F ` A ) ` N ) = if ( N e. A , ( ( 1 / 3 ) ^ N ) , 0 ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | rpnnen2.1 | |- F = ( x e. ~P NN |-> ( n e. NN |-> if ( n e. x , ( ( 1 / 3 ) ^ n ) , 0 ) ) ) |
|
| 2 | nnex | |- NN e. _V |
|
| 3 | 2 | elpw2 | |- ( A e. ~P NN <-> A C_ NN ) |
| 4 | eleq2 | |- ( x = A -> ( n e. x <-> n e. A ) ) |
|
| 5 | 4 | ifbid | |- ( x = A -> if ( n e. x , ( ( 1 / 3 ) ^ n ) , 0 ) = if ( n e. A , ( ( 1 / 3 ) ^ n ) , 0 ) ) |
| 6 | 5 | mpteq2dv | |- ( x = A -> ( n e. NN |-> if ( n e. x , ( ( 1 / 3 ) ^ n ) , 0 ) ) = ( n e. NN |-> if ( n e. A , ( ( 1 / 3 ) ^ n ) , 0 ) ) ) |
| 7 | 2 | mptex | |- ( n e. NN |-> if ( n e. A , ( ( 1 / 3 ) ^ n ) , 0 ) ) e. _V |
| 8 | 6 1 7 | fvmpt | |- ( A e. ~P NN -> ( F ` A ) = ( n e. NN |-> if ( n e. A , ( ( 1 / 3 ) ^ n ) , 0 ) ) ) |
| 9 | 3 8 | sylbir | |- ( A C_ NN -> ( F ` A ) = ( n e. NN |-> if ( n e. A , ( ( 1 / 3 ) ^ n ) , 0 ) ) ) |
| 10 | 9 | fveq1d | |- ( A C_ NN -> ( ( F ` A ) ` N ) = ( ( n e. NN |-> if ( n e. A , ( ( 1 / 3 ) ^ n ) , 0 ) ) ` N ) ) |
| 11 | eleq1 | |- ( n = N -> ( n e. A <-> N e. A ) ) |
|
| 12 | oveq2 | |- ( n = N -> ( ( 1 / 3 ) ^ n ) = ( ( 1 / 3 ) ^ N ) ) |
|
| 13 | 11 12 | ifbieq1d | |- ( n = N -> if ( n e. A , ( ( 1 / 3 ) ^ n ) , 0 ) = if ( N e. A , ( ( 1 / 3 ) ^ N ) , 0 ) ) |
| 14 | eqid | |- ( n e. NN |-> if ( n e. A , ( ( 1 / 3 ) ^ n ) , 0 ) ) = ( n e. NN |-> if ( n e. A , ( ( 1 / 3 ) ^ n ) , 0 ) ) |
|
| 15 | ovex | |- ( ( 1 / 3 ) ^ N ) e. _V |
|
| 16 | c0ex | |- 0 e. _V |
|
| 17 | 15 16 | ifex | |- if ( N e. A , ( ( 1 / 3 ) ^ N ) , 0 ) e. _V |
| 18 | 13 14 17 | fvmpt | |- ( N e. NN -> ( ( n e. NN |-> if ( n e. A , ( ( 1 / 3 ) ^ n ) , 0 ) ) ` N ) = if ( N e. A , ( ( 1 / 3 ) ^ N ) , 0 ) ) |
| 19 | 10 18 | sylan9eq | |- ( ( A C_ NN /\ N e. NN ) -> ( ( F ` A ) ` N ) = if ( N e. A , ( ( 1 / 3 ) ^ N ) , 0 ) ) |