Theorem submod 18694

Description: The order of an element is the same in a subgroup. (Contributed by Stefan O'Rear, 12-Sep-2015.) (Proof shortened by AV, 5-Oct-2020.)

Hypotheses

Ref	Expression
submod.h	⊢ 𝐻 = (𝐺 ↾s 𝑌)
submod.o	⊢ 𝑂 = (od‘𝐺)
submod.p	⊢ 𝑃 = (od‘𝐻)

Assertion

Ref	Expression
submod	⊢ ((𝑌 ∈ (SubMnd‘𝐺) ∧ 𝐴 ∈ 𝑌) → (𝑂‘𝐴) = (𝑃‘𝐴))

Proof of Theorem submod

Dummy variable 𝑥 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		simpll 765	. . . . . 6 ⊢ (((𝑌 ∈ (SubMnd‘𝐺) ∧ 𝐴 ∈ 𝑌) ∧ 𝑥 ∈ ℕ) → 𝑌 ∈ (SubMnd‘𝐺))
2		nnnn0 11905	. . . . . . 7 ⊢ (𝑥 ∈ ℕ → 𝑥 ∈ ℕ0)
3	2	adantl 484	. . . . . 6 ⊢ (((𝑌 ∈ (SubMnd‘𝐺) ∧ 𝐴 ∈ 𝑌) ∧ 𝑥 ∈ ℕ) → 𝑥 ∈ ℕ0)
4		simplr 767	. . . . . 6 ⊢ (((𝑌 ∈ (SubMnd‘𝐺) ∧ 𝐴 ∈ 𝑌) ∧ 𝑥 ∈ ℕ) → 𝐴 ∈ 𝑌)
5		eqid 2821	. . . . . . 7 ⊢ (.g‘𝐺) = (.g‘𝐺)
6		submod.h	. . . . . . 7 ⊢ 𝐻 = (𝐺 ↾s 𝑌)
7		eqid 2821	. . . . . . 7 ⊢ (.g‘𝐻) = (.g‘𝐻)
8	5, 6, 7	submmulg 18271	. . . . . 6 ⊢ ((𝑌 ∈ (SubMnd‘𝐺) ∧ 𝑥 ∈ ℕ0 ∧ 𝐴 ∈ 𝑌) → (𝑥(.g‘𝐺)𝐴) = (𝑥(.g‘𝐻)𝐴))
9	1, 3, 4, 8	syl3anc 1367	. . . . 5 ⊢ (((𝑌 ∈ (SubMnd‘𝐺) ∧ 𝐴 ∈ 𝑌) ∧ 𝑥 ∈ ℕ) → (𝑥(.g‘𝐺)𝐴) = (𝑥(.g‘𝐻)𝐴))
10		eqid 2821	. . . . . . 7 ⊢ (0g‘𝐺) = (0g‘𝐺)
11	6, 10	subm0 17980	. . . . . 6 ⊢ (𝑌 ∈ (SubMnd‘𝐺) → (0g‘𝐺) = (0g‘𝐻))
12	11	ad2antrr 724	. . . . 5 ⊢ (((𝑌 ∈ (SubMnd‘𝐺) ∧ 𝐴 ∈ 𝑌) ∧ 𝑥 ∈ ℕ) → (0g‘𝐺) = (0g‘𝐻))
13	9, 12	eqeq12d 2837	. . . 4 ⊢ (((𝑌 ∈ (SubMnd‘𝐺) ∧ 𝐴 ∈ 𝑌) ∧ 𝑥 ∈ ℕ) → ((𝑥(.g‘𝐺)𝐴) = (0g‘𝐺) ↔ (𝑥(.g‘𝐻)𝐴) = (0g‘𝐻)))
14	13	rabbidva 3478	. . 3 ⊢ ((𝑌 ∈ (SubMnd‘𝐺) ∧ 𝐴 ∈ 𝑌) → {𝑥 ∈ ℕ ∣ (𝑥(.g‘𝐺)𝐴) = (0g‘𝐺)} = {𝑥 ∈ ℕ ∣ (𝑥(.g‘𝐻)𝐴) = (0g‘𝐻)})
15		eqeq1 2825	. . . 4 ⊢ ({𝑥 ∈ ℕ ∣ (𝑥(.g‘𝐺)𝐴) = (0g‘𝐺)} = {𝑥 ∈ ℕ ∣ (𝑥(.g‘𝐻)𝐴) = (0g‘𝐻)} → ({𝑥 ∈ ℕ ∣ (𝑥(.g‘𝐺)𝐴) = (0g‘𝐺)} = ∅ ↔ {𝑥 ∈ ℕ ∣ (𝑥(.g‘𝐻)𝐴) = (0g‘𝐻)} = ∅))
16		infeq1 8940	. . . 4 ⊢ ({𝑥 ∈ ℕ ∣ (𝑥(.g‘𝐺)𝐴) = (0g‘𝐺)} = {𝑥 ∈ ℕ ∣ (𝑥(.g‘𝐻)𝐴) = (0g‘𝐻)} → inf({𝑥 ∈ ℕ ∣ (𝑥(.g‘𝐺)𝐴) = (0g‘𝐺)}, ℝ, < ) = inf({𝑥 ∈ ℕ ∣ (𝑥(.g‘𝐻)𝐴) = (0g‘𝐻)}, ℝ, < ))
17	15, 16	ifbieq2d 4492	. . 3 ⊢ ({𝑥 ∈ ℕ ∣ (𝑥(.g‘𝐺)𝐴) = (0g‘𝐺)} = {𝑥 ∈ ℕ ∣ (𝑥(.g‘𝐻)𝐴) = (0g‘𝐻)} → if({𝑥 ∈ ℕ ∣ (𝑥(.g‘𝐺)𝐴) = (0g‘𝐺)} = ∅, 0, inf({𝑥 ∈ ℕ ∣ (𝑥(.g‘𝐺)𝐴) = (0g‘𝐺)}, ℝ, < )) = if({𝑥 ∈ ℕ ∣ (𝑥(.g‘𝐻)𝐴) = (0g‘𝐻)} = ∅, 0, inf({𝑥 ∈ ℕ ∣ (𝑥(.g‘𝐻)𝐴) = (0g‘𝐻)}, ℝ, < )))
18	14, 17	syl 17	. 2 ⊢ ((𝑌 ∈ (SubMnd‘𝐺) ∧ 𝐴 ∈ 𝑌) → if({𝑥 ∈ ℕ ∣ (𝑥(.g‘𝐺)𝐴) = (0g‘𝐺)} = ∅, 0, inf({𝑥 ∈ ℕ ∣ (𝑥(.g‘𝐺)𝐴) = (0g‘𝐺)}, ℝ, < )) = if({𝑥 ∈ ℕ ∣ (𝑥(.g‘𝐻)𝐴) = (0g‘𝐻)} = ∅, 0, inf({𝑥 ∈ ℕ ∣ (𝑥(.g‘𝐻)𝐴) = (0g‘𝐻)}, ℝ, < )))
19		eqid 2821	. . . . 5 ⊢ (Base‘𝐺) = (Base‘𝐺)
20	19	submss 17974	. . . 4 ⊢ (𝑌 ∈ (SubMnd‘𝐺) → 𝑌 ⊆ (Base‘𝐺))
21	20	sselda 3967	. . 3 ⊢ ((𝑌 ∈ (SubMnd‘𝐺) ∧ 𝐴 ∈ 𝑌) → 𝐴 ∈ (Base‘𝐺))
22		submod.o	. . . 4 ⊢ 𝑂 = (od‘𝐺)
23		eqid 2821	. . . 4 ⊢ {𝑥 ∈ ℕ ∣ (𝑥(.g‘𝐺)𝐴) = (0g‘𝐺)} = {𝑥 ∈ ℕ ∣ (𝑥(.g‘𝐺)𝐴) = (0g‘𝐺)}
24	19, 5, 10, 22, 23	odval 18662	. . 3 ⊢ (𝐴 ∈ (Base‘𝐺) → (𝑂‘𝐴) = if({𝑥 ∈ ℕ ∣ (𝑥(.g‘𝐺)𝐴) = (0g‘𝐺)} = ∅, 0, inf({𝑥 ∈ ℕ ∣ (𝑥(.g‘𝐺)𝐴) = (0g‘𝐺)}, ℝ, < )))
25	21, 24	syl 17	. 2 ⊢ ((𝑌 ∈ (SubMnd‘𝐺) ∧ 𝐴 ∈ 𝑌) → (𝑂‘𝐴) = if({𝑥 ∈ ℕ ∣ (𝑥(.g‘𝐺)𝐴) = (0g‘𝐺)} = ∅, 0, inf({𝑥 ∈ ℕ ∣ (𝑥(.g‘𝐺)𝐴) = (0g‘𝐺)}, ℝ, < )))
26		simpr 487	. . . 4 ⊢ ((𝑌 ∈ (SubMnd‘𝐺) ∧ 𝐴 ∈ 𝑌) → 𝐴 ∈ 𝑌)
27	20	adantr 483	. . . . 5 ⊢ ((𝑌 ∈ (SubMnd‘𝐺) ∧ 𝐴 ∈ 𝑌) → 𝑌 ⊆ (Base‘𝐺))
28	6, 19	ressbas2 16555	. . . . 5 ⊢ (𝑌 ⊆ (Base‘𝐺) → 𝑌 = (Base‘𝐻))
29	27, 28	syl 17	. . . 4 ⊢ ((𝑌 ∈ (SubMnd‘𝐺) ∧ 𝐴 ∈ 𝑌) → 𝑌 = (Base‘𝐻))
30	26, 29	eleqtrd 2915	. . 3 ⊢ ((𝑌 ∈ (SubMnd‘𝐺) ∧ 𝐴 ∈ 𝑌) → 𝐴 ∈ (Base‘𝐻))
31		eqid 2821	. . . 4 ⊢ (Base‘𝐻) = (Base‘𝐻)
32		eqid 2821	. . . 4 ⊢ (0g‘𝐻) = (0g‘𝐻)
33		submod.p	. . . 4 ⊢ 𝑃 = (od‘𝐻)
34		eqid 2821	. . . 4 ⊢ {𝑥 ∈ ℕ ∣ (𝑥(.g‘𝐻)𝐴) = (0g‘𝐻)} = {𝑥 ∈ ℕ ∣ (𝑥(.g‘𝐻)𝐴) = (0g‘𝐻)}
35	31, 7, 32, 33, 34	odval 18662	. . 3 ⊢ (𝐴 ∈ (Base‘𝐻) → (𝑃‘𝐴) = if({𝑥 ∈ ℕ ∣ (𝑥(.g‘𝐻)𝐴) = (0g‘𝐻)} = ∅, 0, inf({𝑥 ∈ ℕ ∣ (𝑥(.g‘𝐻)𝐴) = (0g‘𝐻)}, ℝ, < )))
36	30, 35	syl 17	. 2 ⊢ ((𝑌 ∈ (SubMnd‘𝐺) ∧ 𝐴 ∈ 𝑌) → (𝑃‘𝐴) = if({𝑥 ∈ ℕ ∣ (𝑥(.g‘𝐻)𝐴) = (0g‘𝐻)} = ∅, 0, inf({𝑥 ∈ ℕ ∣ (𝑥(.g‘𝐻)𝐴) = (0g‘𝐻)}, ℝ, < )))
37	18, 25, 36	3eqtr4d 2866	1 ⊢ ((𝑌 ∈ (SubMnd‘𝐺) ∧ 𝐴 ∈ 𝑌) → (𝑂‘𝐴) = (𝑃‘𝐴))

Syntax hints:   → wi 4   ∧ wa 398   = wceq 1537   ∈ wcel 2114  {crab 3142   ⊆ wss 3936  ∅c0 4291  ifcif 4467  ‘cfv 6355  (class class class)co 7156  infcinf 8905  ℝcr 10536  0cc0 10537   < clt 10675  ℕcn 11638  ℕ₀cn0 11898  Basecbs 16483   ↾_s cress 16484  0_gc0g 16713  SubMndcsubmnd 17955  ._gcmg 18224  odcod 18652

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1796  ax-4 1810  ax-5 1911  ax-6 1970  ax-7 2015  ax-8 2116  ax-9 2124  ax-10 2145  ax-11 2161  ax-12 2177  ax-ext 2793  ax-sep 5203  ax-nul 5210  ax-pow 5266  ax-pr 5330  ax-un 7461  ax-cnex 10593  ax-resscn 10594  ax-1cn 10595  ax-icn 10596  ax-addcl 10597  ax-addrcl 10598  ax-mulcl 10599  ax-mulrcl 10600  ax-mulcom 10601  ax-addass 10602  ax-mulass 10603  ax-distr 10604  ax-i2m1 10605  ax-1ne0 10606  ax-1rid 10607  ax-rnegex 10608  ax-rrecex 10609  ax-cnre 10610  ax-pre-lttri 10611  ax-pre-lttrn 10612  ax-pre-ltadd 10613  ax-pre-mulgt0 10614

This theorem depends on definitions:  df-bi 209  df-an 399  df-or 844  df-3or 1084  df-3an 1085  df-tru 1540  df-ex 1781  df-nf 1785  df-sb 2070  df-mo 2622  df-eu 2654  df-clab 2800  df-cleq 2814  df-clel 2893  df-nfc 2963  df-ne 3017  df-nel 3124  df-ral 3143  df-rex 3144  df-reu 3145  df-rmo 3146  df-rab 3147  df-v 3496  df-sbc 3773  df-csb 3884  df-dif 3939  df-un 3941  df-in 3943  df-ss 3952  df-pss 3954  df-nul 4292  df-if 4468  df-pw 4541  df-sn 4568  df-pr 4570  df-tp 4572  df-op 4574  df-uni 4839  df-iun 4921  df-br 5067  df-opab 5129  df-mpt 5147  df-tr 5173  df-id 5460  df-eprel 5465  df-po 5474  df-so 5475  df-fr 5514  df-we 5516  df-xp 5561  df-rel 5562  df-cnv 5563  df-co 5564  df-dm 5565  df-rn 5566  df-res 5567  df-ima 5568  df-pred 6148  df-ord 6194  df-on 6195  df-lim 6196  df-suc 6197  df-iota 6314  df-fun 6357  df-fn 6358  df-f 6359  df-f1 6360  df-fo 6361  df-f1o 6362  df-fv 6363  df-riota 7114  df-ov 7159  df-oprab 7160  df-mpo 7161  df-om 7581  df-1st 7689  df-2nd 7690  df-wrecs 7947  df-recs 8008  df-rdg 8046  df-er 8289  df-en 8510  df-dom 8511  df-sdom 8512  df-sup 8906  df-inf 8907  df-pnf 10677  df-mnf 10678  df-xr 10679  df-ltxr 10680  df-le 10681  df-sub 10872  df-neg 10873  df-nn 11639  df-2 11701  df-n0 11899  df-z 11983  df-uz 12245  df-seq 13371  df-ndx 16486  df-slot 16487  df-base 16489  df-sets 16490  df-ress 16491  df-plusg 16578  df-0g 16715  df-mgm 17852  df-sgrp 17901  df-mnd 17912  df-submnd 17957  df-mulg 18225  df-od 18656

This theorem is referenced by:  subgod  18695