Metamath Proof Explorer


Theorem mbfi1fseqlem2

Description: Lemma for mbfi1fseq . (Contributed by Mario Carneiro, 16-Aug-2014) (Revised by Mario Carneiro, 23-Aug-2014)

Ref Expression
Hypotheses mbfi1fseq.1
|- ( ph -> F e. MblFn )
mbfi1fseq.2
|- ( ph -> F : RR --> ( 0 [,) +oo ) )
mbfi1fseq.3
|- J = ( m e. NN , y e. RR |-> ( ( |_ ` ( ( F ` y ) x. ( 2 ^ m ) ) ) / ( 2 ^ m ) ) )
mbfi1fseq.4
|- G = ( m e. NN |-> ( x e. RR |-> if ( x e. ( -u m [,] m ) , if ( ( m J x ) <_ m , ( m J x ) , m ) , 0 ) ) )
Assertion mbfi1fseqlem2
|- ( A e. NN -> ( G ` A ) = ( x e. RR |-> if ( x e. ( -u A [,] A ) , if ( ( A J x ) <_ A , ( A J x ) , A ) , 0 ) ) )

Proof

Step Hyp Ref Expression
1 mbfi1fseq.1
 |-  ( ph -> F e. MblFn )
2 mbfi1fseq.2
 |-  ( ph -> F : RR --> ( 0 [,) +oo ) )
3 mbfi1fseq.3
 |-  J = ( m e. NN , y e. RR |-> ( ( |_ ` ( ( F ` y ) x. ( 2 ^ m ) ) ) / ( 2 ^ m ) ) )
4 mbfi1fseq.4
 |-  G = ( m e. NN |-> ( x e. RR |-> if ( x e. ( -u m [,] m ) , if ( ( m J x ) <_ m , ( m J x ) , m ) , 0 ) ) )
5 negeq
 |-  ( m = A -> -u m = -u A )
6 id
 |-  ( m = A -> m = A )
7 5 6 oveq12d
 |-  ( m = A -> ( -u m [,] m ) = ( -u A [,] A ) )
8 7 eleq2d
 |-  ( m = A -> ( x e. ( -u m [,] m ) <-> x e. ( -u A [,] A ) ) )
9 oveq1
 |-  ( m = A -> ( m J x ) = ( A J x ) )
10 9 6 breq12d
 |-  ( m = A -> ( ( m J x ) <_ m <-> ( A J x ) <_ A ) )
11 10 9 6 ifbieq12d
 |-  ( m = A -> if ( ( m J x ) <_ m , ( m J x ) , m ) = if ( ( A J x ) <_ A , ( A J x ) , A ) )
12 8 11 ifbieq1d
 |-  ( m = A -> if ( x e. ( -u m [,] m ) , if ( ( m J x ) <_ m , ( m J x ) , m ) , 0 ) = if ( x e. ( -u A [,] A ) , if ( ( A J x ) <_ A , ( A J x ) , A ) , 0 ) )
13 12 mpteq2dv
 |-  ( m = A -> ( x e. RR |-> if ( x e. ( -u m [,] m ) , if ( ( m J x ) <_ m , ( m J x ) , m ) , 0 ) ) = ( x e. RR |-> if ( x e. ( -u A [,] A ) , if ( ( A J x ) <_ A , ( A J x ) , A ) , 0 ) ) )
14 reex
 |-  RR e. _V
15 14 mptex
 |-  ( x e. RR |-> if ( x e. ( -u A [,] A ) , if ( ( A J x ) <_ A , ( A J x ) , A ) , 0 ) ) e. _V
16 13 4 15 fvmpt
 |-  ( A e. NN -> ( G ` A ) = ( x e. RR |-> if ( x e. ( -u A [,] A ) , if ( ( A J x ) <_ A , ( A J x ) , A ) , 0 ) ) )