Theorem revfv 13512

Description: Reverse of a word at a point. (Contributed by Stefan O'Rear, 26-Aug-2015.)

Assertion

Ref	Expression
revfv	|- ( ( W e. Word A /\ X e. ( 0..^ ( # ` W ) ) ) -> ( (reverse ` W ) ` X ) = ( W ` ( ( ( # ` W ) - 1 ) - X ) ) )

Proof of Theorem revfv

Dummy variable x is distinct from all other variables.

Step	Hyp	Ref	Expression
1		revval 13509	. . 3 |- ( W e. Word A -> (reverse ` W ) = ( x e. ( 0..^ ( # ` W ) ) |-> ( W ` ( ( ( # ` W ) - 1 ) - x ) ) ) )
2	1	fveq1d 6193	. 2 |- ( W e. Word A -> ( (reverse ` W ) ` X ) = ( ( x e. ( 0..^ ( # ` W ) ) |-> ( W ` ( ( ( # ` W ) - 1 ) - x ) ) ) ` X ) )
3		oveq2 6658	. . . 4 |- ( x = X -> ( ( ( # ` W ) - 1 ) - x ) = ( ( ( # ` W ) - 1 ) - X ) )
4	3	fveq2d 6195	. . 3 |- ( x = X -> ( W ` ( ( ( # ` W ) - 1 ) - x ) ) = ( W ` ( ( ( # ` W ) - 1 ) - X ) ) )
5		eqid 2622	. . 3 |- ( x e. ( 0..^ ( # ` W ) ) |-> ( W ` ( ( ( # ` W ) - 1 ) - x ) ) ) = ( x e. ( 0..^ ( # ` W ) ) |-> ( W ` ( ( ( # ` W ) - 1 ) - x ) ) )
6		fvex 6201	. . 3 |- ( W ` ( ( ( # ` W ) - 1 ) - X ) ) e. _V
7	4, 5, 6	fvmpt 6282	. 2 |- ( X e. ( 0..^ ( # ` W ) ) -> ( ( x e. ( 0..^ ( # ` W ) ) |-> ( W ` ( ( ( # ` W ) - 1 ) - x ) ) ) ` X ) = ( W ` ( ( ( # ` W ) - 1 ) - X ) ) )
8	2, 7	sylan9eq 2676	1 |- ( ( W e. Word A /\ X e. ( 0..^ ( # ` W ) ) ) -> ( (reverse ` W ) ` X ) = ( W ` ( ( ( # ` W ) - 1 ) - X ) ) )

Syntax hints:   -> wi 4   /\ wa 384   = wceq 1483   e. wcel 1990   |-> cmpt 4729   ` cfv 5888  (class class class)co 6650   0cc0 9936   1c1 9937   - cmin 10266  ..^cfzo 12465   #chash 13117  Word cword 13291  reversecreverse 13297

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1722  ax-4 1737  ax-5 1839  ax-6 1888  ax-7 1935  ax-9 1999  ax-10 2019  ax-11 2034  ax-12 2047  ax-13 2246  ax-ext 2602  ax-rep 4771  ax-sep 4781  ax-nul 4789  ax-pr 4906

This theorem depends on definitions:  df-bi 197  df-or 385  df-an 386  df-3an 1039  df-tru 1486  df-ex 1705  df-nf 1710  df-sb 1881  df-eu 2474  df-mo 2475  df-clab 2609  df-cleq 2615  df-clel 2618  df-nfc 2753  df-ne 2795  df-ral 2917  df-rex 2918  df-reu 2919  df-rab 2921  df-v 3202  df-sbc 3436  df-csb 3534  df-dif 3577  df-un 3579  df-in 3581  df-ss 3588  df-nul 3916  df-if 4087  df-sn 4178  df-pr 4180  df-op 4184  df-uni 4437  df-iun 4522  df-br 4654  df-opab 4713  df-mpt 4730  df-id 5024  df-xp 5120  df-rel 5121  df-cnv 5122  df-co 5123  df-dm 5124  df-rn 5125  df-res 5126  df-ima 5127  df-iota 5851  df-fun 5890  df-fn 5891  df-f 5892  df-f1 5893  df-fo 5894  df-f1o 5895  df-fv 5896  df-ov 6653  df-reverse 13305

This theorem is referenced by:  revs1  13514  revccat  13515  revrev  13516  revco  13580