Theorem fproddccvg 12123

Description: The sequence of partial products of a finite product converges to the whole product. (Contributed by Scott Fenton, 4-Dec-2017.)

Hypotheses

Ref	Expression
prodmo.1	|- F = ( k e. ZZ |-> if ( k e. A , B , 1 ) )
prodmo.2	|- ( ( ph /\ k e. A ) -> B e. CC )
prodrbdc.dc	|- ( ( ph /\ k e. ( ZZ>= ` M ) ) -> DECID k e. A )
prodrb.3	|- ( ph -> N e. ( ZZ>= ` M ) )
fprodcvg.4	|- ( ph -> A C_ ( M ... N ) )

Assertion

Ref	Expression
fproddccvg	|- ( ph -> seq M ( x. , F ) ~~> ( seq M ( x. , F ) ` N ) )

Distinct variable groups:   A, k   k, F   ph, k   k, M   k, N

Allowed substitution hint:   B( k)

Proof of Theorem fproddccvg

Dummy variables n v m are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		eqid 2229	. 2 |- ( ZZ>= ` N ) = ( ZZ>= ` N )
2		prodrb.3	. . 3 |- ( ph -> N e. ( ZZ>= ` M ) )
3		eluzelz 9755	. . 3 |- ( N e. ( ZZ>= ` M ) -> N e. ZZ )
4	2, 3	syl 14	. 2 |- ( ph -> N e. ZZ )
5		seqex 10701	. . 3 |- seq M ( x. , F ) e. _V
6	5	a1i 9	. 2 |- ( ph -> seq M ( x. , F ) e. _V )
7		eqid 2229	. . . 4 |- ( ZZ>= ` M ) = ( ZZ>= ` M )
8		eluzel2 9750	. . . . 5 |- ( N e. ( ZZ>= ` M ) -> M e. ZZ )
9	2, 8	syl 14	. . . 4 |- ( ph -> M e. ZZ )
10		eluzelz 9755	. . . . . . 7 |- ( k e. ( ZZ>= ` M ) -> k e. ZZ )
11	10	adantl 277	. . . . . 6 |- ( ( ph /\ k e. ( ZZ>= ` M ) ) -> k e. ZZ )
12		iftrue 3608	. . . . . . . . 9 |- ( k e. A -> if ( k e. A , B , 1 ) = B )
13	12	adantl 277	. . . . . . . 8 |- ( ( ( ph /\ k e. ( ZZ>= ` M ) ) /\ k e. A ) -> if ( k e. A , B , 1 ) = B )
14		prodmo.2	. . . . . . . . 9 |- ( ( ph /\ k e. A ) -> B e. CC )
15	14	adantlr 477	. . . . . . . 8 |- ( ( ( ph /\ k e. ( ZZ>= ` M ) ) /\ k e. A ) -> B e. CC )
16	13, 15	eqeltrd 2306	. . . . . . 7 |- ( ( ( ph /\ k e. ( ZZ>= ` M ) ) /\ k e. A ) -> if ( k e. A , B , 1 ) e. CC )
17		iffalse 3611	. . . . . . . . 9 |- ( -. k e. A -> if ( k e. A , B , 1 ) = 1 )
18		ax-1cn 8115	. . . . . . . . 9 |- 1 e. CC
19	17, 18	eqeltrdi 2320	. . . . . . . 8 |- ( -. k e. A -> if ( k e. A , B , 1 ) e. CC )
20	19	adantl 277	. . . . . . 7 |- ( ( ( ph /\ k e. ( ZZ>= ` M ) ) /\ -. k e. A ) -> if ( k e. A , B , 1 ) e. CC )
21		prodrbdc.dc	. . . . . . . 8 |- ( ( ph /\ k e. ( ZZ>= ` M ) ) -> DECID k e. A )
22		exmiddc 841	. . . . . . . 8 |- (DECID k e. A -> ( k e. A \/ -. k e. A ) )
23	21, 22	syl 14	. . . . . . 7 |- ( ( ph /\ k e. ( ZZ>= ` M ) ) -> ( k e. A \/ -. k e. A ) )
24	16, 20, 23	mpjaodan 803	. . . . . 6 |- ( ( ph /\ k e. ( ZZ>= ` M ) ) -> if ( k e. A , B , 1 ) e. CC )
25		prodmo.1	. . . . . . 7 |- F = ( k e. ZZ |-> if ( k e. A , B , 1 ) )
26	25	fvmpt2 5726	. . . . . 6 |- ( ( k e. ZZ /\ if ( k e. A , B , 1 ) e. CC ) -> ( F ` k ) = if ( k e. A , B , 1 ) )
27	11, 24, 26	syl2anc 411	. . . . 5 |- ( ( ph /\ k e. ( ZZ>= ` M ) ) -> ( F ` k ) = if ( k e. A , B , 1 ) )
28	27, 24	eqeltrd 2306	. . . 4 |- ( ( ph /\ k e. ( ZZ>= ` M ) ) -> ( F ` k ) e. CC )
29	7, 9, 28	prodf 12089	. . 3 |- ( ph -> seq M ( x. , F ) : ( ZZ>= ` M ) --> CC )
30	29, 2	ffvelcdmd 5779	. 2 |- ( ph -> ( seq M ( x. , F ) ` N ) e. CC )
31		mulrid 8166	. . . . 5 |- ( m e. CC -> ( m x. 1 ) = m )
32	31	adantl 277	. . . 4 |- ( ( ( ph /\ n e. ( ZZ>= ` N ) ) /\ m e. CC ) -> ( m x. 1 ) = m )
33	2	adantr 276	. . . 4 |- ( ( ph /\ n e. ( ZZ>= ` N ) ) -> N e. ( ZZ>= ` M ) )
34		simpr 110	. . . 4 |- ( ( ph /\ n e. ( ZZ>= ` N ) ) -> n e. ( ZZ>= ` N ) )
35	9	adantr 276	. . . . . 6 |- ( ( ph /\ n e. ( ZZ>= ` N ) ) -> M e. ZZ )
36	28	adantlr 477	. . . . . 6 |- ( ( ( ph /\ n e. ( ZZ>= ` N ) ) /\ k e. ( ZZ>= ` M ) ) -> ( F ` k ) e. CC )
37	7, 35, 36	prodf 12089	. . . . 5 |- ( ( ph /\ n e. ( ZZ>= ` N ) ) -> seq M ( x. , F ) : ( ZZ>= ` M ) --> CC )
38	37, 33	ffvelcdmd 5779	. . . 4 |- ( ( ph /\ n e. ( ZZ>= ` N ) ) -> ( seq M ( x. , F ) ` N ) e. CC )
39		elfzuz 10246	. . . . . 6 |- ( m e. ( ( N + 1 ) ... n ) -> m e. ( ZZ>= ` ( N + 1 ) ) )
40		eluzelz 9755	. . . . . . . . 9 |- ( m e. ( ZZ>= ` ( N + 1 ) ) -> m e. ZZ )
41	40	adantl 277	. . . . . . . 8 |- ( ( ph /\ m e. ( ZZ>= ` ( N + 1 ) ) ) -> m e. ZZ )
42		fprodcvg.4	. . . . . . . . . . . 12 |- ( ph -> A C_ ( M ... N ) )
43	42	sseld 3224	. . . . . . . . . . 11 |- ( ph -> ( m e. A -> m e. ( M ... N ) ) )
44		fznuz 10327	. . . . . . . . . . 11 |- ( m e. ( M ... N ) -> -. m e. ( ZZ>= ` ( N + 1 ) ) )
45	43, 44	syl6 33	. . . . . . . . . 10 |- ( ph -> ( m e. A -> -. m e. ( ZZ>= ` ( N + 1 ) ) ) )
46	45	con2d 627	. . . . . . . . 9 |- ( ph -> ( m e. ( ZZ>= ` ( N + 1 ) ) -> -. m e. A ) )
47	46	imp 124	. . . . . . . 8 |- ( ( ph /\ m e. ( ZZ>= ` ( N + 1 ) ) ) -> -. m e. A )
48	41, 47	eldifd 3208	. . . . . . 7 |- ( ( ph /\ m e. ( ZZ>= ` ( N + 1 ) ) ) -> m e. ( ZZ \ A ) )
49		fveqeq2 5644	. . . . . . . 8 |- ( k = m -> ( ( F ` k ) = 1 <-> ( F ` m ) = 1 ) )
50		eldifi 3327	. . . . . . . . . 10 |- ( k e. ( ZZ \ A ) -> k e. ZZ )
51		eldifn 3328	. . . . . . . . . . . 12 |- ( k e. ( ZZ \ A ) -> -. k e. A )
52	51, 17	syl 14	. . . . . . . . . . 11 |- ( k e. ( ZZ \ A ) -> if ( k e. A , B , 1 ) = 1 )
53	52, 18	eqeltrdi 2320	. . . . . . . . . 10 |- ( k e. ( ZZ \ A ) -> if ( k e. A , B , 1 ) e. CC )
54	50, 53, 26	syl2anc 411	. . . . . . . . 9 |- ( k e. ( ZZ \ A ) -> ( F ` k ) = if ( k e. A , B , 1 ) )
55	54, 52	eqtrd 2262	. . . . . . . 8 |- ( k e. ( ZZ \ A ) -> ( F ` k ) = 1 )
56	49, 55	vtoclga 2868	. . . . . . 7 |- ( m e. ( ZZ \ A ) -> ( F ` m ) = 1 )
57	48, 56	syl 14	. . . . . 6 |- ( ( ph /\ m e. ( ZZ>= ` ( N + 1 ) ) ) -> ( F ` m ) = 1 )
58	39, 57	sylan2 286	. . . . 5 |- ( ( ph /\ m e. ( ( N + 1 ) ... n ) ) -> ( F ` m ) = 1 )
59	58	adantlr 477	. . . 4 |- ( ( ( ph /\ n e. ( ZZ>= ` N ) ) /\ m e. ( ( N + 1 ) ... n ) ) -> ( F ` m ) = 1 )
60		fveq2 5635	. . . . . 6 |- ( k = m -> ( F ` k ) = ( F ` m ) )
61	60	eleq1d 2298	. . . . 5 |- ( k = m -> ( ( F ` k ) e. CC <-> ( F ` m ) e. CC ) )
62	28	ralrimiva 2603	. . . . . 6 |- ( ph -> A. k e. ( ZZ>= ` M ) ( F ` k ) e. CC )
63	62	ad2antrr 488	. . . . 5 |- ( ( ( ph /\ n e. ( ZZ>= ` N ) ) /\ m e. ( ZZ>= ` M ) ) -> A. k e. ( ZZ>= ` M ) ( F ` k ) e. CC )
64		simpr 110	. . . . 5 |- ( ( ( ph /\ n e. ( ZZ>= ` N ) ) /\ m e. ( ZZ>= ` M ) ) -> m e. ( ZZ>= ` M ) )
65	61, 63, 64	rspcdva 2913	. . . 4 |- ( ( ( ph /\ n e. ( ZZ>= ` N ) ) /\ m e. ( ZZ>= ` M ) ) -> ( F ` m ) e. CC )
66		mulcl 8149	. . . . 5 |- ( ( m e. CC /\ v e. CC ) -> ( m x. v ) e. CC )
67	66	adantl 277	. . . 4 |- ( ( ( ph /\ n e. ( ZZ>= ` N ) ) /\ ( m e. CC /\ v e. CC ) ) -> ( m x. v ) e. CC )
68	32, 33, 34, 38, 59, 65, 67	seq3id2 10778	. . 3 |- ( ( ph /\ n e. ( ZZ>= ` N ) ) -> ( seq M ( x. , F ) ` N ) = ( seq M ( x. , F ) ` n ) )
69	68	eqcomd 2235	. 2 |- ( ( ph /\ n e. ( ZZ>= ` N ) ) -> ( seq M ( x. , F ) ` n ) = ( seq M ( x. , F ) ` N ) )
70	1, 4, 6, 30, 69	climconst 11841	1 |- ( ph -> seq M ( x. , F ) ~~> ( seq M ( x. , F ) ` N ) )

Syntax hints:   -. wn 3   -> wi 4   /\ wa 104   \/ wo 713  DECID wdc 839   = wceq 1395   e. wcel 2200   A.wral 2508   _Vcvv 2800   \ cdif 3195   C_ wss 3198   ifcif 3603   class class class wbr 4086   |-> cmpt 4148   ` cfv 5324  (class class class)co 6013   CCcc 8020   1c1 8023   + caddc 8025   x. cmul 8027   ZZcz 9469   ZZ>=cuz 9745   ...cfz 10233   seqcseq 10699   ~~> cli 11829

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-mulrcl 8121  ax-addcom 8122  ax-mulcom 8123  ax-addass 8124  ax-mulass 8125  ax-distr 8126  ax-i2m1 8127  ax-0lt1 8128  ax-1rid 8129  ax-0id 8130  ax-rnegex 8131  ax-precex 8132  ax-cnre 8133  ax-pre-ltirr 8134  ax-pre-ltwlin 8135  ax-pre-lttrn 8136  ax-pre-apti 8137  ax-pre-ltadd 8138  ax-pre-mulgt0 8139  ax-pre-mulext 8140

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-rmo 2516  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-po 4391  df-iso 4392  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-pnf 8206  df-mnf 8207  df-xr 8208  df-ltxr 8209  df-le 8210  df-sub 8342  df-neg 8343  df-reap 8745  df-ap 8752  df-div 8843  df-inn 9134  df-2 9192  df-n0 9393  df-z 9470  df-uz 9746  df-rp 9879  df-fz 10234  df-seqfrec 10700  df-exp 10791  df-cj 11393  df-rsqrt 11549  df-abs 11550  df-clim 11830

This theorem is referenced by:  prodmodclem2a  12127