Metamath Proof Explorer


Theorem imasmhm

Description: Given a function F with homomorphic properties, build the image of a monoid. (Contributed by Thierry Arnoux, 2-Apr-2025)

Ref Expression
Hypotheses imasmhm.b 𝐵 = ( Base ‘ 𝑊 )
imasmhm.f ( 𝜑𝐹 : 𝐵𝐶 )
imasmhm.1 + = ( +g𝑊 )
imasmhm.2 ( ( 𝜑 ∧ ( 𝑎𝐵𝑏𝐵 ) ∧ ( 𝑝𝐵𝑞𝐵 ) ) → ( ( ( 𝐹𝑎 ) = ( 𝐹𝑝 ) ∧ ( 𝐹𝑏 ) = ( 𝐹𝑞 ) ) → ( 𝐹 ‘ ( 𝑎 + 𝑏 ) ) = ( 𝐹 ‘ ( 𝑝 + 𝑞 ) ) ) )
imasmhm.w ( 𝜑𝑊 ∈ Mnd )
Assertion imasmhm ( 𝜑 → ( ( 𝐹s 𝑊 ) ∈ Mnd ∧ 𝐹 ∈ ( 𝑊 MndHom ( 𝐹s 𝑊 ) ) ) )

Proof

Step Hyp Ref Expression
1 imasmhm.b 𝐵 = ( Base ‘ 𝑊 )
2 imasmhm.f ( 𝜑𝐹 : 𝐵𝐶 )
3 imasmhm.1 + = ( +g𝑊 )
4 imasmhm.2 ( ( 𝜑 ∧ ( 𝑎𝐵𝑏𝐵 ) ∧ ( 𝑝𝐵𝑞𝐵 ) ) → ( ( ( 𝐹𝑎 ) = ( 𝐹𝑝 ) ∧ ( 𝐹𝑏 ) = ( 𝐹𝑞 ) ) → ( 𝐹 ‘ ( 𝑎 + 𝑏 ) ) = ( 𝐹 ‘ ( 𝑝 + 𝑞 ) ) ) )
5 imasmhm.w ( 𝜑𝑊 ∈ Mnd )
6 eqidd ( 𝜑 → ( 𝐹s 𝑊 ) = ( 𝐹s 𝑊 ) )
7 1 a1i ( 𝜑𝐵 = ( Base ‘ 𝑊 ) )
8 fimadmfo ( 𝐹 : 𝐵𝐶𝐹 : 𝐵onto→ ( 𝐹𝐵 ) )
9 2 8 syl ( 𝜑𝐹 : 𝐵onto→ ( 𝐹𝐵 ) )
10 eqid ( 0g𝑊 ) = ( 0g𝑊 )
11 6 7 3 9 4 5 10 imasmnd ( 𝜑 → ( ( 𝐹s 𝑊 ) ∈ Mnd ∧ ( 𝐹 ‘ ( 0g𝑊 ) ) = ( 0g ‘ ( 𝐹s 𝑊 ) ) ) )
12 11 simpld ( 𝜑 → ( 𝐹s 𝑊 ) ∈ Mnd )
13 eqid ( Base ‘ ( 𝐹s 𝑊 ) ) = ( Base ‘ ( 𝐹s 𝑊 ) )
14 eqid ( +g ‘ ( 𝐹s 𝑊 ) ) = ( +g ‘ ( 𝐹s 𝑊 ) )
15 eqid ( 0g ‘ ( 𝐹s 𝑊 ) ) = ( 0g ‘ ( 𝐹s 𝑊 ) )
16 fof ( 𝐹 : 𝐵onto→ ( 𝐹𝐵 ) → 𝐹 : 𝐵 ⟶ ( 𝐹𝐵 ) )
17 9 16 syl ( 𝜑𝐹 : 𝐵 ⟶ ( 𝐹𝐵 ) )
18 6 7 9 5 imasbas ( 𝜑 → ( 𝐹𝐵 ) = ( Base ‘ ( 𝐹s 𝑊 ) ) )
19 18 feq3d ( 𝜑 → ( 𝐹 : 𝐵 ⟶ ( 𝐹𝐵 ) ↔ 𝐹 : 𝐵 ⟶ ( Base ‘ ( 𝐹s 𝑊 ) ) ) )
20 17 19 mpbid ( 𝜑𝐹 : 𝐵 ⟶ ( Base ‘ ( 𝐹s 𝑊 ) ) )
21 9 4 6 7 5 3 14 imasaddval ( ( 𝜑𝑥𝐵𝑦𝐵 ) → ( ( 𝐹𝑥 ) ( +g ‘ ( 𝐹s 𝑊 ) ) ( 𝐹𝑦 ) ) = ( 𝐹 ‘ ( 𝑥 + 𝑦 ) ) )
22 21 3expb ( ( 𝜑 ∧ ( 𝑥𝐵𝑦𝐵 ) ) → ( ( 𝐹𝑥 ) ( +g ‘ ( 𝐹s 𝑊 ) ) ( 𝐹𝑦 ) ) = ( 𝐹 ‘ ( 𝑥 + 𝑦 ) ) )
23 22 eqcomd ( ( 𝜑 ∧ ( 𝑥𝐵𝑦𝐵 ) ) → ( 𝐹 ‘ ( 𝑥 + 𝑦 ) ) = ( ( 𝐹𝑥 ) ( +g ‘ ( 𝐹s 𝑊 ) ) ( 𝐹𝑦 ) ) )
24 11 simprd ( 𝜑 → ( 𝐹 ‘ ( 0g𝑊 ) ) = ( 0g ‘ ( 𝐹s 𝑊 ) ) )
25 1 13 3 14 10 15 5 12 20 23 24 ismhmd ( 𝜑𝐹 ∈ ( 𝑊 MndHom ( 𝐹s 𝑊 ) ) )
26 12 25 jca ( 𝜑 → ( ( 𝐹s 𝑊 ) ∈ Mnd ∧ 𝐹 ∈ ( 𝑊 MndHom ( 𝐹s 𝑊 ) ) ) )