Theorem mnd1 13528

Description: The (smallest) structure representing a trivial monoid consists of one element. (Contributed by AV, 28-Apr-2019.) (Proof shortened by AV, 11-Feb-2020.)

Hypothesis

Ref	Expression
mnd1.m	⊢ 𝑀 = {⟨(Base‘ndx), {𝐼}⟩, ⟨(+g‘ndx), {⟨⟨𝐼, 𝐼⟩, 𝐼⟩}⟩}

Assertion

Ref	Expression
mnd1	⊢ (𝐼 ∈ 𝑉 → 𝑀 ∈ Mnd)

Proof of Theorem mnd1

Dummy variables 𝑥 𝑦 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		mnd1.m	. . . 4 ⊢ 𝑀 = {⟨(Base‘ndx), {𝐼}⟩, ⟨(+g‘ndx), {⟨⟨𝐼, 𝐼⟩, 𝐼⟩}⟩}
2	1	sgrp1 13484	. . 3 ⊢ (𝐼 ∈ 𝑉 → 𝑀 ∈ Smgrp)
3		df-ov 6016	. . . . . 6 ⊢ (𝐼{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝐼) = ({⟨⟨𝐼, 𝐼⟩, 𝐼⟩}‘⟨𝐼, 𝐼⟩)
4		opexg 4318	. . . . . . . 8 ⊢ ((𝐼 ∈ 𝑉 ∧ 𝐼 ∈ 𝑉) → ⟨𝐼, 𝐼⟩ ∈ V)
5	4	anidms 397	. . . . . . 7 ⊢ (𝐼 ∈ 𝑉 → ⟨𝐼, 𝐼⟩ ∈ V)
6		fvsng 5845	. . . . . . 7 ⊢ ((⟨𝐼, 𝐼⟩ ∈ V ∧ 𝐼 ∈ 𝑉) → ({⟨⟨𝐼, 𝐼⟩, 𝐼⟩}‘⟨𝐼, 𝐼⟩) = 𝐼)
7	5, 6	mpancom 422	. . . . . 6 ⊢ (𝐼 ∈ 𝑉 → ({⟨⟨𝐼, 𝐼⟩, 𝐼⟩}‘⟨𝐼, 𝐼⟩) = 𝐼)
8	3, 7	eqtrid 2274	. . . . 5 ⊢ (𝐼 ∈ 𝑉 → (𝐼{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝐼) = 𝐼)
9		oveq2 6021	. . . . . . . 8 ⊢ (𝑦 = 𝐼 → (𝐼{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝑦) = (𝐼{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝐼))
10		id 19	. . . . . . . 8 ⊢ (𝑦 = 𝐼 → 𝑦 = 𝐼)
11	9, 10	eqeq12d 2244	. . . . . . 7 ⊢ (𝑦 = 𝐼 → ((𝐼{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝑦) = 𝑦 ↔ (𝐼{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝐼) = 𝐼))
12		oveq1 6020	. . . . . . . 8 ⊢ (𝑦 = 𝐼 → (𝑦{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝐼) = (𝐼{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝐼))
13	12, 10	eqeq12d 2244	. . . . . . 7 ⊢ (𝑦 = 𝐼 → ((𝑦{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝐼) = 𝑦 ↔ (𝐼{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝐼) = 𝐼))
14	11, 13	anbi12d 473	. . . . . 6 ⊢ (𝑦 = 𝐼 → (((𝐼{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝑦) = 𝑦 ∧ (𝑦{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝐼) = 𝑦) ↔ ((𝐼{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝐼) = 𝐼 ∧ (𝐼{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝐼) = 𝐼)))
15	14	ralsng 3707	. . . . 5 ⊢ (𝐼 ∈ 𝑉 → (∀𝑦 ∈ {𝐼} ((𝐼{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝑦) = 𝑦 ∧ (𝑦{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝐼) = 𝑦) ↔ ((𝐼{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝐼) = 𝐼 ∧ (𝐼{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝐼) = 𝐼)))
16	8, 8, 15	mpbir2and 950	. . . 4 ⊢ (𝐼 ∈ 𝑉 → ∀𝑦 ∈ {𝐼} ((𝐼{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝑦) = 𝑦 ∧ (𝑦{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝐼) = 𝑦))
17		oveq1 6020	. . . . . . 7 ⊢ (𝑥 = 𝐼 → (𝑥{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝑦) = (𝐼{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝑦))
18	17	eqeq1d 2238	. . . . . 6 ⊢ (𝑥 = 𝐼 → ((𝑥{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝑦) = 𝑦 ↔ (𝐼{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝑦) = 𝑦))
19	18	ovanraleqv 6037	. . . . 5 ⊢ (𝑥 = 𝐼 → (∀𝑦 ∈ {𝐼} ((𝑥{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝑦) = 𝑦 ∧ (𝑦{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝑥) = 𝑦) ↔ ∀𝑦 ∈ {𝐼} ((𝐼{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝑦) = 𝑦 ∧ (𝑦{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝐼) = 𝑦)))
20	19	rexsng 3708	. . . 4 ⊢ (𝐼 ∈ 𝑉 → (∃𝑥 ∈ {𝐼}∀𝑦 ∈ {𝐼} ((𝑥{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝑦) = 𝑦 ∧ (𝑦{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝑥) = 𝑦) ↔ ∀𝑦 ∈ {𝐼} ((𝐼{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝑦) = 𝑦 ∧ (𝑦{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝐼) = 𝑦)))
21	16, 20	mpbird 167	. . 3 ⊢ (𝐼 ∈ 𝑉 → ∃𝑥 ∈ {𝐼}∀𝑦 ∈ {𝐼} ((𝑥{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝑦) = 𝑦 ∧ (𝑦{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝑥) = 𝑦))
22		snexg 4272	. . . . . 6 ⊢ (𝐼 ∈ 𝑉 → {𝐼} ∈ V)
23		opexg 4318	. . . . . . . 8 ⊢ ((⟨𝐼, 𝐼⟩ ∈ V ∧ 𝐼 ∈ 𝑉) → ⟨⟨𝐼, 𝐼⟩, 𝐼⟩ ∈ V)
24	5, 23	mpancom 422	. . . . . . 7 ⊢ (𝐼 ∈ 𝑉 → ⟨⟨𝐼, 𝐼⟩, 𝐼⟩ ∈ V)
25		snexg 4272	. . . . . . 7 ⊢ (⟨⟨𝐼, 𝐼⟩, 𝐼⟩ ∈ V → {⟨⟨𝐼, 𝐼⟩, 𝐼⟩} ∈ V)
26	24, 25	syl 14	. . . . . 6 ⊢ (𝐼 ∈ 𝑉 → {⟨⟨𝐼, 𝐼⟩, 𝐼⟩} ∈ V)
27	1	grpbaseg 13200	. . . . . 6 ⊢ (({𝐼} ∈ V ∧ {⟨⟨𝐼, 𝐼⟩, 𝐼⟩} ∈ V) → {𝐼} = (Base‘𝑀))
28	22, 26, 27	syl2anc 411	. . . . 5 ⊢ (𝐼 ∈ 𝑉 → {𝐼} = (Base‘𝑀))
29	1	grpplusgg 13201	. . . . . . . . . 10 ⊢ (({𝐼} ∈ V ∧ {⟨⟨𝐼, 𝐼⟩, 𝐼⟩} ∈ V) → {⟨⟨𝐼, 𝐼⟩, 𝐼⟩} = (+g‘𝑀))
30	22, 26, 29	syl2anc 411	. . . . . . . . 9 ⊢ (𝐼 ∈ 𝑉 → {⟨⟨𝐼, 𝐼⟩, 𝐼⟩} = (+g‘𝑀))
31	30	oveqd 6030	. . . . . . . 8 ⊢ (𝐼 ∈ 𝑉 → (𝑥{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝑦) = (𝑥(+g‘𝑀)𝑦))
32	31	eqeq1d 2238	. . . . . . 7 ⊢ (𝐼 ∈ 𝑉 → ((𝑥{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝑦) = 𝑦 ↔ (𝑥(+g‘𝑀)𝑦) = 𝑦))
33	30	oveqd 6030	. . . . . . . 8 ⊢ (𝐼 ∈ 𝑉 → (𝑦{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝑥) = (𝑦(+g‘𝑀)𝑥))
34	33	eqeq1d 2238	. . . . . . 7 ⊢ (𝐼 ∈ 𝑉 → ((𝑦{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝑥) = 𝑦 ↔ (𝑦(+g‘𝑀)𝑥) = 𝑦))
35	32, 34	anbi12d 473	. . . . . 6 ⊢ (𝐼 ∈ 𝑉 → (((𝑥{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝑦) = 𝑦 ∧ (𝑦{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝑥) = 𝑦) ↔ ((𝑥(+g‘𝑀)𝑦) = 𝑦 ∧ (𝑦(+g‘𝑀)𝑥) = 𝑦)))
36	28, 35	raleqbidv 2744	. . . . 5 ⊢ (𝐼 ∈ 𝑉 → (∀𝑦 ∈ {𝐼} ((𝑥{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝑦) = 𝑦 ∧ (𝑦{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝑥) = 𝑦) ↔ ∀𝑦 ∈ (Base‘𝑀)((𝑥(+g‘𝑀)𝑦) = 𝑦 ∧ (𝑦(+g‘𝑀)𝑥) = 𝑦)))
37	28, 36	rexeqbidv 2745	. . . 4 ⊢ (𝐼 ∈ 𝑉 → (∃𝑥 ∈ {𝐼}∀𝑦 ∈ {𝐼} ((𝑥{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝑦) = 𝑦 ∧ (𝑦{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝑥) = 𝑦) ↔ ∃𝑥 ∈ (Base‘𝑀)∀𝑦 ∈ (Base‘𝑀)((𝑥(+g‘𝑀)𝑦) = 𝑦 ∧ (𝑦(+g‘𝑀)𝑥) = 𝑦)))
38	37	anbi2d 464	. . 3 ⊢ (𝐼 ∈ 𝑉 → ((𝑀 ∈ Smgrp ∧ ∃𝑥 ∈ {𝐼}∀𝑦 ∈ {𝐼} ((𝑥{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝑦) = 𝑦 ∧ (𝑦{⟨⟨𝐼, 𝐼⟩, 𝐼⟩}𝑥) = 𝑦)) ↔ (𝑀 ∈ Smgrp ∧ ∃𝑥 ∈ (Base‘𝑀)∀𝑦 ∈ (Base‘𝑀)((𝑥(+g‘𝑀)𝑦) = 𝑦 ∧ (𝑦(+g‘𝑀)𝑥) = 𝑦))))
39	2, 21, 38	mpbi2and 949	. 2 ⊢ (𝐼 ∈ 𝑉 → (𝑀 ∈ Smgrp ∧ ∃𝑥 ∈ (Base‘𝑀)∀𝑦 ∈ (Base‘𝑀)((𝑥(+g‘𝑀)𝑦) = 𝑦 ∧ (𝑦(+g‘𝑀)𝑥) = 𝑦)))
40		eqid 2229	. . 3 ⊢ (Base‘𝑀) = (Base‘𝑀)
41		eqid 2229	. . 3 ⊢ (+g‘𝑀) = (+g‘𝑀)
42	40, 41	ismnddef 13491	. 2 ⊢ (𝑀 ∈ Mnd ↔ (𝑀 ∈ Smgrp ∧ ∃𝑥 ∈ (Base‘𝑀)∀𝑦 ∈ (Base‘𝑀)((𝑥(+g‘𝑀)𝑦) = 𝑦 ∧ (𝑦(+g‘𝑀)𝑥) = 𝑦)))
43	39, 42	sylibr 134	1 ⊢ (𝐼 ∈ 𝑉 → 𝑀 ∈ Mnd)

Syntax hints:   → wi 4   ∧ wa 104   = wceq 1395   ∈ wcel 2200  ∀wral 2508  ∃wrex 2509  Vcvv 2800  {csn 3667  {cpr 3668  ⟨cop 3670  ‘cfv 5324  (class class class)co 6013  ndxcnx 13069  Basecbs 13072  +_gcplusg 13150  Smgrpcsgrp 13474  Mndcmnd 13489

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-sep 4205  ax-pow 4262  ax-pr 4297  ax-un 4528  ax-setind 4633  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-i2m1 8127  ax-0lt1 8128  ax-0id 8130  ax-rnegex 8131  ax-pre-ltirr 8134  ax-pre-ltadd 8138

This theorem depends on definitions:  df-bi 117  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-rab 2517  df-v 2802  df-sbc 3030  df-dif 3200  df-un 3202  df-in 3204  df-ss 3211  df-nul 3493  df-pw 3652  df-sn 3673  df-pr 3674  df-op 3676  df-uni 3892  df-int 3927  df-br 4087  df-opab 4149  df-mpt 4150  df-id 4388  df-xp 4729  df-rel 4730  df-cnv 4731  df-co 4732  df-dm 4733  df-rn 4734  df-res 4735  df-iota 5284  df-fun 5326  df-fn 5327  df-fv 5332  df-ov 6016  df-pnf 8206  df-mnf 8207  df-ltxr 8209  df-inn 9134  df-2 9192  df-ndx 13075  df-slot 13076  df-base 13078  df-plusg 13163  df-mgm 13429  df-sgrp 13475  df-mnd 13490

This theorem is referenced by:  grp1  13679  ring1  14062