Theorem infssfzledc 10653

Description: The infimum of a decidable inhabited subset of an integer range is a lower bound for that set. (Contributed by Jim Kingdon, 12-Jun-2026.)

Hypotheses

Ref	Expression
infssfzledc.s	|- S = { n e. ( M ... N ) | ps }
infssfzledc.a	|- ( ph -> A e. S )
infssfzledc.dc	|- ( ( ph /\ n e. ( M ... A ) ) -> DECID ps )

Assertion

Ref	Expression
infssfzledc	|- ( ph -> inf ( S , RR , < ) <_ A )

Distinct variable groups:   A, n   n, M   n, N   ph, n

Allowed substitution hints:   ps( n)   S( n)

Proof of Theorem infssfzledc

Step	Hyp	Ref	Expression
1		infssfzledc.s	. . . 4 |- S = { n e. ( M ... N ) | ps }
2		elfzuz 10407	. . . . . . . 8 |- ( n e. ( M ... N ) -> n e. ( ZZ>= ` M ) )
3	2	ad2antrl 494	. . . . . . 7 |- ( ( ph /\ ( n e. ( M ... N ) /\ ps ) ) -> n e. ( ZZ>= ` M ) )
4		elfzle2 10415	. . . . . . . 8 |- ( n e. ( M ... N ) -> n <_ N )
5	4	ad2antrl 494	. . . . . . 7 |- ( ( ph /\ ( n e. ( M ... N ) /\ ps ) ) -> n <_ N )
6		simprr 537	. . . . . . 7 |- ( ( ph /\ ( n e. ( M ... N ) /\ ps ) ) -> ps )
7	3, 5, 6	jca32 310	. . . . . 6 |- ( ( ph /\ ( n e. ( M ... N ) /\ ps ) ) -> ( n e. ( ZZ>= ` M ) /\ ( n <_ N /\ ps ) ) )
8		simprl 535	. . . . . . . 8 |- ( ( ph /\ ( n e. ( ZZ>= ` M ) /\ ( n <_ N /\ ps ) ) ) -> n e. ( ZZ>= ` M ) )
9		simprrl 545	. . . . . . . . 9 |- ( ( ph /\ ( n e. ( ZZ>= ` M ) /\ ( n <_ N /\ ps ) ) ) -> n <_ N )
10		eluzelz 9914	. . . . . . . . . . 11 |- ( n e. ( ZZ>= ` M ) -> n e. ZZ )
11	10	adantr 276	. . . . . . . . . 10 |- ( ( n e. ( ZZ>= ` M ) /\ ( n <_ N /\ ps ) ) -> n e. ZZ )
12		infssfzledc.a	. . . . . . . . . . . . 13 |- ( ph -> A e. S )
13	1	eleq2i 2305	. . . . . . . . . . . . . 14 |- ( A e. S <-> A e. { n e. ( M ... N ) | ps } )
14		nfcv 2392	. . . . . . . . . . . . . . 15 |- F/_ n ( M ... N )
15	14	elrabsf 3090	. . . . . . . . . . . . . 14 |- ( A e. { n e. ( M ... N ) | ps } <-> ( A e. ( M ... N ) /\ [. A / n ]. ps ) )
16	13, 15	bitri 184	. . . . . . . . . . . . 13 |- ( A e. S <-> ( A e. ( M ... N ) /\ [. A / n ]. ps ) )
17	12, 16	sylib 122	. . . . . . . . . . . 12 |- ( ph -> ( A e. ( M ... N ) /\ [. A / n ]. ps ) )
18	17	simpld 112	. . . . . . . . . . 11 |- ( ph -> A e. ( M ... N ) )
19		elfzel2 10409	. . . . . . . . . . 11 |- ( A e. ( M ... N ) -> N e. ZZ )
20	18, 19	syl 14	. . . . . . . . . 10 |- ( ph -> N e. ZZ )
21		eluz 9918	. . . . . . . . . 10 |- ( ( n e. ZZ /\ N e. ZZ ) -> ( N e. ( ZZ>= ` n ) <-> n <_ N ) )
22	11, 20, 21	syl2anr 290	. . . . . . . . 9 |- ( ( ph /\ ( n e. ( ZZ>= ` M ) /\ ( n <_ N /\ ps ) ) ) -> ( N e. ( ZZ>= ` n ) <-> n <_ N ) )
23	9, 22	mpbird 167	. . . . . . . 8 |- ( ( ph /\ ( n e. ( ZZ>= ` M ) /\ ( n <_ N /\ ps ) ) ) -> N e. ( ZZ>= ` n ) )
24		elfzuzb 10405	. . . . . . . 8 |- ( n e. ( M ... N ) <-> ( n e. ( ZZ>= ` M ) /\ N e. ( ZZ>= ` n ) ) )
25	8, 23, 24	sylanbrc 421	. . . . . . 7 |- ( ( ph /\ ( n e. ( ZZ>= ` M ) /\ ( n <_ N /\ ps ) ) ) -> n e. ( M ... N ) )
26		simprrr 546	. . . . . . 7 |- ( ( ph /\ ( n e. ( ZZ>= ` M ) /\ ( n <_ N /\ ps ) ) ) -> ps )
27	25, 26	jca 306	. . . . . 6 |- ( ( ph /\ ( n e. ( ZZ>= ` M ) /\ ( n <_ N /\ ps ) ) ) -> ( n e. ( M ... N ) /\ ps ) )
28	7, 27	impbida 604	. . . . 5 |- ( ph -> ( ( n e. ( M ... N ) /\ ps ) <-> ( n e. ( ZZ>= ` M ) /\ ( n <_ N /\ ps ) ) ) )
29	28	rabbidva2 2805	. . . 4 |- ( ph -> { n e. ( M ... N ) | ps } = { n e. ( ZZ>= ` M ) | ( n <_ N /\ ps ) } )
30	1, 29	eqtrid 2283	. . 3 |- ( ph -> S = { n e. ( ZZ>= ` M ) | ( n <_ N /\ ps ) } )
31	30	infeq1d 7346	. 2 |- ( ph -> inf ( S , RR , < ) = inf ( { n e. ( ZZ>= ` M ) | ( n <_ N /\ ps ) } , RR , < ) )
32		elfzel1 10410	. . . 4 |- ( A e. ( M ... N ) -> M e. ZZ )
33	18, 32	syl 14	. . 3 |- ( ph -> M e. ZZ )
34		eqid 2238	. . 3 |- { n e. ( ZZ>= ` M ) | ( n <_ N /\ ps ) } = { n e. ( ZZ>= ` M ) | ( n <_ N /\ ps ) }
35	12, 30	eleqtrd 2317	. . 3 |- ( ph -> A e. { n e. ( ZZ>= ` M ) | ( n <_ N /\ ps ) } )
36		elfzelz 10411	. . . . 5 |- ( n e. ( M ... A ) -> n e. ZZ )
37		zdcle 9704	. . . . 5 |- ( ( n e. ZZ /\ N e. ZZ ) -> DECID n <_ N )
38	36, 20, 37	syl2anr 290	. . . 4 |- ( ( ph /\ n e. ( M ... A ) ) -> DECID n <_ N )
39		infssfzledc.dc	. . . 4 |- ( ( ph /\ n e. ( M ... A ) ) -> DECID ps )
40	38, 39	dcand 945	. . 3 |- ( ( ph /\ n e. ( M ... A ) ) -> DECID ( n <_ N /\ ps ) )
41	33, 34, 35, 40	infssuzledc 10650	. 2 |- ( ph -> inf ( { n e. ( ZZ>= ` M ) | ( n <_ N /\ ps ) } , RR , < ) <_ A )
42	31, 41	eqbrtrd 4150	1 |- ( ph -> inf ( S , RR , < ) <_ A )

Syntax hints:   -> wi 4   /\ wa 104   <-> wb 105  DECID wdc 846   = wceq 1402   e. wcel 2209   {crab 2532   [.wsbc 3051   class class class wbr 4128   ` cfv 5375  (class class class)co 6079  infcinf 7317   RRcr 8172   < clt 8354   <_ cle 8355   ZZcz 9627   ZZ>=cuz 9904   ...cfz 10394

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 623  ax-in2 624  ax-io 721  ax-5 1500  ax-7 1501  ax-gen 1502  ax-ie1 1546  ax-ie2 1547  ax-8 1557  ax-10 1558  ax-11 1559  ax-i12 1560  ax-bndl 1562  ax-4 1563  ax-17 1579  ax-i9 1583  ax-ial 1587  ax-i5r 1588  ax-14 2212  ax-ext 2220  ax-sep 4247  ax-pow 4309  ax-pr 4344  ax-un 4576  ax-setind 4682  ax-cnex 8264  ax-resscn 8265  ax-1cn 8266  ax-1re 8267  ax-icn 8268  ax-addcl 8269  ax-addrcl 8270  ax-mulcl 8271  ax-addcom 8273  ax-addass 8275  ax-distr 8277  ax-i2m1 8278  ax-0lt1 8279  ax-0id 8281  ax-rnegex 8282  ax-cnre 8284  ax-pre-ltirr 8285  ax-pre-ltwlin 8286  ax-pre-lttrn 8287  ax-pre-apti 8288  ax-pre-ltadd 8289

This theorem depends on definitions:  df-bi 117  df-dc 847  df-3or 1010  df-3an 1011  df-tru 1405  df-fal 1408  df-nf 1514  df-sb 1816  df-eu 2089  df-mo 2090  df-clab 2225  df-cleq 2231  df-clel 2234  df-nfc 2381  df-ne 2421  df-nel 2516  df-ral 2533  df-rex 2534  df-reu 2535  df-rmo 2536  df-rab 2537  df-v 2823  df-sbc 3052  df-csb 3148  df-dif 3222  df-un 3224  df-in 3226  df-ss 3233  df-pw 3690  df-sn 3714  df-pr 3715  df-op 3717  df-uni 3934  df-int 3969  df-iun 4012  df-br 4129  df-opab 4191  df-mpt 4192  df-id 4436  df-xp 4778  df-rel 4779  df-cnv 4780  df-co 4781  df-dm 4782  df-rn 4783  df-res 4784  df-ima 4785  df-iota 5335  df-fun 5377  df-fn 5378  df-f 5379  df-fv 5383  df-riota 6032  df-ov 6082  df-oprab 6083  df-mpo 6084  df-1st 6368  df-2nd 6369  df-sup 7318  df-inf 7319  df-pnf 8356  df-mnf 8357  df-xr 8358  df-ltxr 8359  df-le 8360  df-sub 8493  df-neg 8494  df-inn 9288  df-n0 9547  df-z 9628  df-uz 9905  df-fz 10395  df-fzo 10533

This theorem is referenced by:  ballotfilemsle  13231