Theorem swrdccat3b 11311

Description: A suffix of a concatenation is either a suffix of the second concatenated word or a concatenation of a suffix of the first word with the second word. (Contributed by Alexander van der Vekens, 31-Mar-2018.) (Revised by Alexander van der Vekens, 30-May-2018.) (Proof shortened by AV, 14-Oct-2022.)

Hypothesis

Ref	Expression
swrdccatin2.l	|- L = (♯ ` A )

Assertion

Ref	Expression
swrdccat3b	|- ( ( A e. Word V /\ B e. Word V ) -> ( M e. ( 0 ... ( L + (♯ ` B ) ) ) -> ( ( A ++ B ) substr <. M , ( L + (♯ ` B ) ) >. ) = if ( L <_ M , ( B substr <. ( M - L ) , (♯ ` B ) >. ) , ( ( A substr <. M , L >. ) ++ B ) ) ) )

Proof of Theorem swrdccat3b

Step	Hyp	Ref	Expression
1		simpl 109	. . . 4 |- ( ( ( A e. Word V /\ B e. Word V ) /\ M e. ( 0 ... ( L + (♯ ` B ) ) ) ) -> ( A e. Word V /\ B e. Word V ) )
2		simpr 110	. . . 4 |- ( ( ( A e. Word V /\ B e. Word V ) /\ M e. ( 0 ... ( L + (♯ ` B ) ) ) ) -> M e. ( 0 ... ( L + (♯ ` B ) ) ) )
3		elfzubelfz 10261	. . . . 5 |- ( M e. ( 0 ... ( L + (♯ ` B ) ) ) -> ( L + (♯ ` B ) ) e. ( 0 ... ( L + (♯ ` B ) ) ) )
4	3	adantl 277	. . . 4 |- ( ( ( A e. Word V /\ B e. Word V ) /\ M e. ( 0 ... ( L + (♯ ` B ) ) ) ) -> ( L + (♯ ` B ) ) e. ( 0 ... ( L + (♯ ` B ) ) ) )
5		swrdccatin2.l	. . . . . 6 |- L = (♯ ` A )
6	5	pfxccat3 11305	. . . . 5 |- ( ( A e. Word V /\ B e. Word V ) -> ( ( M e. ( 0 ... ( L + (♯ ` B ) ) ) /\ ( L + (♯ ` B ) ) e. ( 0 ... ( L + (♯ ` B ) ) ) ) -> ( ( A ++ B ) substr <. M , ( L + (♯ ` B ) ) >. ) = if ( ( L + (♯ ` B ) ) <_ L , ( A substr <. M , ( L + (♯ ` B ) ) >. ) , if ( L <_ M , ( B substr <. ( M - L ) , ( ( L + (♯ ` B ) ) - L ) >. ) , ( ( A substr <. M , L >. ) ++ ( B prefix ( ( L + (♯ ` B ) ) - L ) ) ) ) ) ) )
7	6	imp 124	. . . 4 |- ( ( ( A e. Word V /\ B e. Word V ) /\ ( M e. ( 0 ... ( L + (♯ ` B ) ) ) /\ ( L + (♯ ` B ) ) e. ( 0 ... ( L + (♯ ` B ) ) ) ) ) -> ( ( A ++ B ) substr <. M , ( L + (♯ ` B ) ) >. ) = if ( ( L + (♯ ` B ) ) <_ L , ( A substr <. M , ( L + (♯ ` B ) ) >. ) , if ( L <_ M , ( B substr <. ( M - L ) , ( ( L + (♯ ` B ) ) - L ) >. ) , ( ( A substr <. M , L >. ) ++ ( B prefix ( ( L + (♯ ` B ) ) - L ) ) ) ) ) )
8	1, 2, 4, 7	syl12anc 1269	. . 3 |- ( ( ( A e. Word V /\ B e. Word V ) /\ M e. ( 0 ... ( L + (♯ ` B ) ) ) ) -> ( ( A ++ B ) substr <. M , ( L + (♯ ` B ) ) >. ) = if ( ( L + (♯ ` B ) ) <_ L , ( A substr <. M , ( L + (♯ ` B ) ) >. ) , if ( L <_ M , ( B substr <. ( M - L ) , ( ( L + (♯ ` B ) ) - L ) >. ) , ( ( A substr <. M , L >. ) ++ ( B prefix ( ( L + (♯ ` B ) ) - L ) ) ) ) ) )
9	5	swrdccat3blem 11310	. . . 4 |- ( ( ( ( A e. Word V /\ B e. Word V ) /\ M e. ( 0 ... ( L + (♯ ` B ) ) ) ) /\ ( L + (♯ ` B ) ) <_ L ) -> if ( L <_ M , ( B substr <. ( M - L ) , (♯ ` B ) >. ) , ( ( A substr <. M , L >. ) ++ B ) ) = ( A substr <. M , ( L + (♯ ` B ) ) >. ) )
10		iftrue 3608	. . . . . 6 |- ( L <_ M -> if ( L <_ M , ( B substr <. ( M - L ) , (♯ ` B ) >. ) , ( ( A substr <. M , L >. ) ++ B ) ) = ( B substr <. ( M - L ) , (♯ ` B ) >. ) )
11	10	3ad2ant3 1044	. . . . 5 |- ( ( ( ( A e. Word V /\ B e. Word V ) /\ M e. ( 0 ... ( L + (♯ ` B ) ) ) ) /\ -. ( L + (♯ ` B ) ) <_ L /\ L <_ M ) -> if ( L <_ M , ( B substr <. ( M - L ) , (♯ ` B ) >. ) , ( ( A substr <. M , L >. ) ++ B ) ) = ( B substr <. ( M - L ) , (♯ ` B ) >. ) )
12		lencl 11107	. . . . . . . . . . . 12 |- ( A e. Word V -> (♯ ` A ) e. NN0 )
13	12	nn0cnd 9447	. . . . . . . . . . 11 |- ( A e. Word V -> (♯ ` A ) e. CC )
14		lencl 11107	. . . . . . . . . . . 12 |- ( B e. Word V -> (♯ ` B ) e. NN0 )
15	14	nn0cnd 9447	. . . . . . . . . . 11 |- ( B e. Word V -> (♯ ` B ) e. CC )
16	5	eqcomi 2233	. . . . . . . . . . . . 13 |- (♯ ` A ) = L
17	16	eleq1i 2295	. . . . . . . . . . . 12 |- ( (♯ ` A ) e. CC <-> L e. CC )
18		pncan2 8376	. . . . . . . . . . . 12 |- ( ( L e. CC /\ (♯ ` B ) e. CC ) -> ( ( L + (♯ ` B ) ) - L ) = (♯ ` B ) )
19	17, 18	sylanb 284	. . . . . . . . . . 11 |- ( ( (♯ ` A ) e. CC /\ (♯ ` B ) e. CC ) -> ( ( L + (♯ ` B ) ) - L ) = (♯ ` B ) )
20	13, 15, 19	syl2an 289	. . . . . . . . . 10 |- ( ( A e. Word V /\ B e. Word V ) -> ( ( L + (♯ ` B ) ) - L ) = (♯ ` B ) )
21	20	eqcomd 2235	. . . . . . . . 9 |- ( ( A e. Word V /\ B e. Word V ) -> (♯ ` B ) = ( ( L + (♯ ` B ) ) - L ) )
22	21	adantr 276	. . . . . . . 8 |- ( ( ( A e. Word V /\ B e. Word V ) /\ M e. ( 0 ... ( L + (♯ ` B ) ) ) ) -> (♯ ` B ) = ( ( L + (♯ ` B ) ) - L ) )
23	22	3ad2ant1 1042	. . . . . . 7 |- ( ( ( ( A e. Word V /\ B e. Word V ) /\ M e. ( 0 ... ( L + (♯ ` B ) ) ) ) /\ -. ( L + (♯ ` B ) ) <_ L /\ L <_ M ) -> (♯ ` B ) = ( ( L + (♯ ` B ) ) - L ) )
24	23	opeq2d 3867	. . . . . 6 |- ( ( ( ( A e. Word V /\ B e. Word V ) /\ M e. ( 0 ... ( L + (♯ ` B ) ) ) ) /\ -. ( L + (♯ ` B ) ) <_ L /\ L <_ M ) -> <. ( M - L ) , (♯ ` B ) >. = <. ( M - L ) , ( ( L + (♯ ` B ) ) - L ) >. )
25	24	oveq2d 6029	. . . . 5 |- ( ( ( ( A e. Word V /\ B e. Word V ) /\ M e. ( 0 ... ( L + (♯ ` B ) ) ) ) /\ -. ( L + (♯ ` B ) ) <_ L /\ L <_ M ) -> ( B substr <. ( M - L ) , (♯ ` B ) >. ) = ( B substr <. ( M - L ) , ( ( L + (♯ ` B ) ) - L ) >. ) )
26	11, 25	eqtrd 2262	. . . 4 |- ( ( ( ( A e. Word V /\ B e. Word V ) /\ M e. ( 0 ... ( L + (♯ ` B ) ) ) ) /\ -. ( L + (♯ ` B ) ) <_ L /\ L <_ M ) -> if ( L <_ M , ( B substr <. ( M - L ) , (♯ ` B ) >. ) , ( ( A substr <. M , L >. ) ++ B ) ) = ( B substr <. ( M - L ) , ( ( L + (♯ ` B ) ) - L ) >. ) )
27		iffalse 3611	. . . . . 6 |- ( -. L <_ M -> if ( L <_ M , ( B substr <. ( M - L ) , (♯ ` B ) >. ) , ( ( A substr <. M , L >. ) ++ B ) ) = ( ( A substr <. M , L >. ) ++ B ) )
28	27	3ad2ant3 1044	. . . . 5 |- ( ( ( ( A e. Word V /\ B e. Word V ) /\ M e. ( 0 ... ( L + (♯ ` B ) ) ) ) /\ -. ( L + (♯ ` B ) ) <_ L /\ -. L <_ M ) -> if ( L <_ M , ( B substr <. ( M - L ) , (♯ ` B ) >. ) , ( ( A substr <. M , L >. ) ++ B ) ) = ( ( A substr <. M , L >. ) ++ B ) )
29	20	adantr 276	. . . . . . . . 9 |- ( ( ( A e. Word V /\ B e. Word V ) /\ M e. ( 0 ... ( L + (♯ ` B ) ) ) ) -> ( ( L + (♯ ` B ) ) - L ) = (♯ ` B ) )
30	29	3ad2ant1 1042	. . . . . . . 8 |- ( ( ( ( A e. Word V /\ B e. Word V ) /\ M e. ( 0 ... ( L + (♯ ` B ) ) ) ) /\ -. ( L + (♯ ` B ) ) <_ L /\ -. L <_ M ) -> ( ( L + (♯ ` B ) ) - L ) = (♯ ` B ) )
31	30	oveq2d 6029	. . . . . . 7 |- ( ( ( ( A e. Word V /\ B e. Word V ) /\ M e. ( 0 ... ( L + (♯ ` B ) ) ) ) /\ -. ( L + (♯ ` B ) ) <_ L /\ -. L <_ M ) -> ( B prefix ( ( L + (♯ ` B ) ) - L ) ) = ( B prefix (♯ ` B ) ) )
32		pfxid 11257	. . . . . . . . 9 |- ( B e. Word V -> ( B prefix (♯ ` B ) ) = B )
33	32	ad2antlr 489	. . . . . . . 8 |- ( ( ( A e. Word V /\ B e. Word V ) /\ M e. ( 0 ... ( L + (♯ ` B ) ) ) ) -> ( B prefix (♯ ` B ) ) = B )
34	33	3ad2ant1 1042	. . . . . . 7 |- ( ( ( ( A e. Word V /\ B e. Word V ) /\ M e. ( 0 ... ( L + (♯ ` B ) ) ) ) /\ -. ( L + (♯ ` B ) ) <_ L /\ -. L <_ M ) -> ( B prefix (♯ ` B ) ) = B )
35	31, 34	eqtr2d 2263	. . . . . 6 |- ( ( ( ( A e. Word V /\ B e. Word V ) /\ M e. ( 0 ... ( L + (♯ ` B ) ) ) ) /\ -. ( L + (♯ ` B ) ) <_ L /\ -. L <_ M ) -> B = ( B prefix ( ( L + (♯ ` B ) ) - L ) ) )
36	35	oveq2d 6029	. . . . 5 |- ( ( ( ( A e. Word V /\ B e. Word V ) /\ M e. ( 0 ... ( L + (♯ ` B ) ) ) ) /\ -. ( L + (♯ ` B ) ) <_ L /\ -. L <_ M ) -> ( ( A substr <. M , L >. ) ++ B ) = ( ( A substr <. M , L >. ) ++ ( B prefix ( ( L + (♯ ` B ) ) - L ) ) ) )
37	28, 36	eqtrd 2262	. . . 4 |- ( ( ( ( A e. Word V /\ B e. Word V ) /\ M e. ( 0 ... ( L + (♯ ` B ) ) ) ) /\ -. ( L + (♯ ` B ) ) <_ L /\ -. L <_ M ) -> if ( L <_ M , ( B substr <. ( M - L ) , (♯ ` B ) >. ) , ( ( A substr <. M , L >. ) ++ B ) ) = ( ( A substr <. M , L >. ) ++ ( B prefix ( ( L + (♯ ` B ) ) - L ) ) ) )
38	4	elfzelzd 10251	. . . . 5 |- ( ( ( A e. Word V /\ B e. Word V ) /\ M e. ( 0 ... ( L + (♯ ` B ) ) ) ) -> ( L + (♯ ` B ) ) e. ZZ )
39	5, 12	eqeltrid 2316	. . . . . . 7 |- ( A e. Word V -> L e. NN0 )
40	39	ad2antrr 488	. . . . . 6 |- ( ( ( A e. Word V /\ B e. Word V ) /\ M e. ( 0 ... ( L + (♯ ` B ) ) ) ) -> L e. NN0 )
41	40	nn0zd 9590	. . . . 5 |- ( ( ( A e. Word V /\ B e. Word V ) /\ M e. ( 0 ... ( L + (♯ ` B ) ) ) ) -> L e. ZZ )
42		zdcle 9546	. . . . 5 |- ( ( ( L + (♯ ` B ) ) e. ZZ /\ L e. ZZ ) -> DECID ( L + (♯ ` B ) ) <_ L )
43	38, 41, 42	syl2anc 411	. . . 4 |- ( ( ( A e. Word V /\ B e. Word V ) /\ M e. ( 0 ... ( L + (♯ ` B ) ) ) ) -> DECID ( L + (♯ ` B ) ) <_ L )
44	41	adantr 276	. . . . 5 |- ( ( ( ( A e. Word V /\ B e. Word V ) /\ M e. ( 0 ... ( L + (♯ ` B ) ) ) ) /\ -. ( L + (♯ ` B ) ) <_ L ) -> L e. ZZ )
45		elfznn0 10339	. . . . . . 7 |- ( M e. ( 0 ... ( L + (♯ ` B ) ) ) -> M e. NN0 )
46	45	ad2antlr 489	. . . . . 6 |- ( ( ( ( A e. Word V /\ B e. Word V ) /\ M e. ( 0 ... ( L + (♯ ` B ) ) ) ) /\ -. ( L + (♯ ` B ) ) <_ L ) -> M e. NN0 )
47	46	nn0zd 9590	. . . . 5 |- ( ( ( ( A e. Word V /\ B e. Word V ) /\ M e. ( 0 ... ( L + (♯ ` B ) ) ) ) /\ -. ( L + (♯ ` B ) ) <_ L ) -> M e. ZZ )
48		zdcle 9546	. . . . 5 |- ( ( L e. ZZ /\ M e. ZZ ) -> DECID L <_ M )
49	44, 47, 48	syl2anc 411	. . . 4 |- ( ( ( ( A e. Word V /\ B e. Word V ) /\ M e. ( 0 ... ( L + (♯ ` B ) ) ) ) /\ -. ( L + (♯ ` B ) ) <_ L ) -> DECID L <_ M )
50	9, 26, 37, 43, 49	2if2dc 3643	. . 3 |- ( ( ( A e. Word V /\ B e. Word V ) /\ M e. ( 0 ... ( L + (♯ ` B ) ) ) ) -> if ( L <_ M , ( B substr <. ( M - L ) , (♯ ` B ) >. ) , ( ( A substr <. M , L >. ) ++ B ) ) = if ( ( L + (♯ ` B ) ) <_ L , ( A substr <. M , ( L + (♯ ` B ) ) >. ) , if ( L <_ M , ( B substr <. ( M - L ) , ( ( L + (♯ ` B ) ) - L ) >. ) , ( ( A substr <. M , L >. ) ++ ( B prefix ( ( L + (♯ ` B ) ) - L ) ) ) ) ) )
51	8, 50	eqtr4d 2265	. 2 |- ( ( ( A e. Word V /\ B e. Word V ) /\ M e. ( 0 ... ( L + (♯ ` B ) ) ) ) -> ( ( A ++ B ) substr <. M , ( L + (♯ ` B ) ) >. ) = if ( L <_ M , ( B substr <. ( M - L ) , (♯ ` B ) >. ) , ( ( A substr <. M , L >. ) ++ B ) ) )
52	51	ex 115	1 |- ( ( A e. Word V /\ B e. Word V ) -> ( M e. ( 0 ... ( L + (♯ ` B ) ) ) -> ( ( A ++ B ) substr <. M , ( L + (♯ ` B ) ) >. ) = if ( L <_ M , ( B substr <. ( M - L ) , (♯ ` B ) >. ) , ( ( A substr <. M , L >. ) ++ B ) ) ) )

Syntax hints:   -. wn 3   -> wi 4   /\ wa 104  DECID wdc 839   /\ w3a 1002   = wceq 1395   e. wcel 2200   ifcif 3603   <.cop 3670   class class class wbr 4086   ` cfv 5324  (class class class)co 6013   CCcc 8020   0cc0 8022   + caddc 8025   <_ cle 8205   - cmin 8340   NN0cn0 9392   ZZcz 9469   ...cfz 10233  ♯chash 11027  Word cword 11103   ++ cconcat 11157   substr csubstr 11216   prefix cpfx 11243

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-in1 617  ax-in2 618  ax-io 714  ax-5 1493  ax-7 1494  ax-gen 1495  ax-ie1 1539  ax-ie2 1540  ax-8 1550  ax-10 1551  ax-11 1552  ax-i12 1553  ax-bndl 1555  ax-4 1556  ax-17 1572  ax-i9 1576  ax-ial 1580  ax-i5r 1581  ax-13 2202  ax-14 2203  ax-ext 2211  ax-coll 4202  ax-sep 4205  ax-nul 4213  ax-pow 4262  ax-pr 4297  ax-un 4528  ax-setind 4633  ax-iinf 4684  ax-cnex 8113  ax-resscn 8114  ax-1cn 8115  ax-1re 8116  ax-icn 8117  ax-addcl 8118  ax-addrcl 8119  ax-mulcl 8120  ax-addcom 8122  ax-addass 8124  ax-distr 8126  ax-i2m1 8127  ax-0lt1 8128  ax-0id 8130  ax-rnegex 8131  ax-cnre 8133  ax-pre-ltirr 8134  ax-pre-ltwlin 8135  ax-pre-lttrn 8136  ax-pre-apti 8137  ax-pre-ltadd 8138

This theorem depends on definitions:  df-bi 117  df-dc 840  df-3or 1003  df-3an 1004  df-tru 1398  df-fal 1401  df-nf 1507  df-sb 1809  df-eu 2080  df-mo 2081  df-clab 2216  df-cleq 2222  df-clel 2225  df-nfc 2361  df-ne 2401  df-nel 2496  df-ral 2513  df-rex 2514  df-reu 2515  df-rab 2517  df-v 2802  df-sbc 3030  df-csb 3126  df-dif 3200  df-un 3202  df-in 3204  df-ss 3211  df-nul 3493  df-if 3604  df-pw 3652  df-sn 3673  df-pr 3674  df-op 3676  df-uni 3892  df-int 3927  df-iun 3970  df-br 4087  df-opab 4149  df-mpt 4150  df-tr 4186  df-id 4388  df-iord 4461  df-on 4463  df-ilim 4464  df-suc 4466  df-iom 4687  df-xp 4729  df-rel 4730  df-cnv 4731  df-co 4732  df-dm 4733  df-rn 4734  df-res 4735  df-ima 4736  df-iota 5284  df-fun 5326  df-fn 5327  df-f 5328  df-f1 5329  df-fo 5330  df-f1o 5331  df-fv 5332  df-riota 5966  df-ov 6016  df-oprab 6017  df-mpo 6018  df-1st 6298  df-2nd 6299  df-recs 6466  df-frec 6552  df-1o 6577  df-er 6697  df-en 6905  df-dom 6906  df-fin 6907  df-pnf 8206  df-mnf 8207  df-xr 8208  df-ltxr 8209  df-le 8210  df-sub 8342  df-neg 8343  df-inn 9134  df-n0 9393  df-z 9470  df-uz 9746  df-fz 10234  df-fzo 10368  df-ihash 11028  df-word 11104  df-concat 11158  df-substr 11217  df-pfx 11244

This theorem is referenced by: (None)