Theorem idmhm 18785

Description: The identity homomorphism on a monoid. (Contributed by AV, 14-Feb-2020.)

Hypothesis

Ref	Expression
idmhm.b	⊢ 𝐵 = (Base‘𝑀)

Assertion

Ref	Expression
idmhm	⊢ (𝑀 ∈ Mnd → ( I ↾ 𝐵) ∈ (𝑀 MndHom 𝑀))

Proof of Theorem idmhm

Dummy variables 𝑎 𝑏 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		id 22	. 2 ⊢ (𝑀 ∈ Mnd → 𝑀 ∈ Mnd)
2		f1oi 6881	. . . 4 ⊢ ( I ↾ 𝐵):𝐵–1-1-onto→𝐵
3		f1of 6843	. . . 4 ⊢ (( I ↾ 𝐵):𝐵–1-1-onto→𝐵 → ( I ↾ 𝐵):𝐵⟶𝐵)
4	2, 3	mp1i 13	. . 3 ⊢ (𝑀 ∈ Mnd → ( I ↾ 𝐵):𝐵⟶𝐵)
5		idmhm.b	. . . . . . . 8 ⊢ 𝐵 = (Base‘𝑀)
6		eqid 2726	. . . . . . . 8 ⊢ (+g‘𝑀) = (+g‘𝑀)
7	5, 6	mndcl 18735	. . . . . . 7 ⊢ ((𝑀 ∈ Mnd ∧ 𝑎 ∈ 𝐵 ∧ 𝑏 ∈ 𝐵) → (𝑎(+g‘𝑀)𝑏) ∈ 𝐵)
8	7	3expb 1117	. . . . . 6 ⊢ ((𝑀 ∈ Mnd ∧ (𝑎 ∈ 𝐵 ∧ 𝑏 ∈ 𝐵)) → (𝑎(+g‘𝑀)𝑏) ∈ 𝐵)
9		fvresi 7187	. . . . . 6 ⊢ ((𝑎(+g‘𝑀)𝑏) ∈ 𝐵 → (( I ↾ 𝐵)‘(𝑎(+g‘𝑀)𝑏)) = (𝑎(+g‘𝑀)𝑏))
10	8, 9	syl 17	. . . . 5 ⊢ ((𝑀 ∈ Mnd ∧ (𝑎 ∈ 𝐵 ∧ 𝑏 ∈ 𝐵)) → (( I ↾ 𝐵)‘(𝑎(+g‘𝑀)𝑏)) = (𝑎(+g‘𝑀)𝑏))
11		fvresi 7187	. . . . . . 7 ⊢ (𝑎 ∈ 𝐵 → (( I ↾ 𝐵)‘𝑎) = 𝑎)
12		fvresi 7187	. . . . . . 7 ⊢ (𝑏 ∈ 𝐵 → (( I ↾ 𝐵)‘𝑏) = 𝑏)
13	11, 12	oveqan12d 7443	. . . . . 6 ⊢ ((𝑎 ∈ 𝐵 ∧ 𝑏 ∈ 𝐵) → ((( I ↾ 𝐵)‘𝑎)(+g‘𝑀)(( I ↾ 𝐵)‘𝑏)) = (𝑎(+g‘𝑀)𝑏))
14	13	adantl 480	. . . . 5 ⊢ ((𝑀 ∈ Mnd ∧ (𝑎 ∈ 𝐵 ∧ 𝑏 ∈ 𝐵)) → ((( I ↾ 𝐵)‘𝑎)(+g‘𝑀)(( I ↾ 𝐵)‘𝑏)) = (𝑎(+g‘𝑀)𝑏))
15	10, 14	eqtr4d 2769	. . . 4 ⊢ ((𝑀 ∈ Mnd ∧ (𝑎 ∈ 𝐵 ∧ 𝑏 ∈ 𝐵)) → (( I ↾ 𝐵)‘(𝑎(+g‘𝑀)𝑏)) = ((( I ↾ 𝐵)‘𝑎)(+g‘𝑀)(( I ↾ 𝐵)‘𝑏)))
16	15	ralrimivva 3191	. . 3 ⊢ (𝑀 ∈ Mnd → ∀𝑎 ∈ 𝐵 ∀𝑏 ∈ 𝐵 (( I ↾ 𝐵)‘(𝑎(+g‘𝑀)𝑏)) = ((( I ↾ 𝐵)‘𝑎)(+g‘𝑀)(( I ↾ 𝐵)‘𝑏)))
17		eqid 2726	. . . . 5 ⊢ (0g‘𝑀) = (0g‘𝑀)
18	5, 17	mndidcl 18742	. . . 4 ⊢ (𝑀 ∈ Mnd → (0g‘𝑀) ∈ 𝐵)
19		fvresi 7187	. . . 4 ⊢ ((0g‘𝑀) ∈ 𝐵 → (( I ↾ 𝐵)‘(0g‘𝑀)) = (0g‘𝑀))
20	18, 19	syl 17	. . 3 ⊢ (𝑀 ∈ Mnd → (( I ↾ 𝐵)‘(0g‘𝑀)) = (0g‘𝑀))
21	4, 16, 20	3jca 1125	. 2 ⊢ (𝑀 ∈ Mnd → (( I ↾ 𝐵):𝐵⟶𝐵 ∧ ∀𝑎 ∈ 𝐵 ∀𝑏 ∈ 𝐵 (( I ↾ 𝐵)‘(𝑎(+g‘𝑀)𝑏)) = ((( I ↾ 𝐵)‘𝑎)(+g‘𝑀)(( I ↾ 𝐵)‘𝑏)) ∧ (( I ↾ 𝐵)‘(0g‘𝑀)) = (0g‘𝑀)))
22	5, 5, 6, 6, 17, 17	ismhm 18775	. 2 ⊢ (( I ↾ 𝐵) ∈ (𝑀 MndHom 𝑀) ↔ ((𝑀 ∈ Mnd ∧ 𝑀 ∈ Mnd) ∧ (( I ↾ 𝐵):𝐵⟶𝐵 ∧ ∀𝑎 ∈ 𝐵 ∀𝑏 ∈ 𝐵 (( I ↾ 𝐵)‘(𝑎(+g‘𝑀)𝑏)) = ((( I ↾ 𝐵)‘𝑎)(+g‘𝑀)(( I ↾ 𝐵)‘𝑏)) ∧ (( I ↾ 𝐵)‘(0g‘𝑀)) = (0g‘𝑀))))
23	1, 1, 21, 22	syl21anbrc 1341	1 ⊢ (𝑀 ∈ Mnd → ( I ↾ 𝐵) ∈ (𝑀 MndHom 𝑀))

Syntax hints:   → wi 4   ∧ wa 394   ∧ w3a 1084   = wceq 1534   ∈ wcel 2099  ∀wral 3051   I cid 5579   ↾ cres 5684  ⟶wf 6550  –1-1-onto→wf1o 6553  ‘cfv 6554  (class class class)co 7424  Basecbs 17213  +_gcplusg 17266  0_gc0g 17454  Mndcmnd 18727   MndHom cmhm 18771

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1790  ax-4 1804  ax-5 1906  ax-6 1964  ax-7 2004  ax-8 2101  ax-9 2109  ax-10 2130  ax-11 2147  ax-12 2167  ax-ext 2697  ax-sep 5304  ax-nul 5311  ax-pow 5369  ax-pr 5433  ax-un 7746

This theorem depends on definitions:  df-bi 206  df-an 395  df-or 846  df-3an 1086  df-tru 1537  df-fal 1547  df-ex 1775  df-nf 1779  df-sb 2061  df-mo 2529  df-eu 2558  df-clab 2704  df-cleq 2718  df-clel 2803  df-nfc 2878  df-ne 2931  df-ral 3052  df-rex 3061  df-rmo 3364  df-reu 3365  df-rab 3420  df-v 3464  df-sbc 3777  df-dif 3950  df-un 3952  df-in 3954  df-ss 3964  df-nul 4326  df-if 4534  df-pw 4609  df-sn 4634  df-pr 4636  df-op 4640  df-uni 4914  df-br 5154  df-opab 5216  df-mpt 5237  df-id 5580  df-xp 5688  df-rel 5689  df-cnv 5690  df-co 5691  df-dm 5692  df-rn 5693  df-res 5694  df-ima 5695  df-iota 6506  df-fun 6556  df-fn 6557  df-f 6558  df-f1 6559  df-fo 6560  df-f1o 6561  df-fv 6562  df-riota 7380  df-ov 7427  df-oprab 7428  df-mpo 7429  df-map 8857  df-0g 17456  df-mgm 18633  df-sgrp 18712  df-mnd 18728  df-mhm 18773

This theorem is referenced by:  idrhm  20472