Metamath Proof Explorer


Definition df-mhm

Description: A monoid homomorphism is a function on the base sets which preserves the binary operation and the identity. (Contributed by Mario Carneiro, 7-Mar-2015)

Ref Expression
Assertion df-mhm MndHom = ( 𝑠 ∈ Mnd , 𝑡 ∈ Mnd ↦ { 𝑓 ∈ ( ( Base ‘ 𝑡 ) ↑m ( Base ‘ 𝑠 ) ) ∣ ( ∀ 𝑥 ∈ ( Base ‘ 𝑠 ) ∀ 𝑦 ∈ ( Base ‘ 𝑠 ) ( 𝑓 ‘ ( 𝑥 ( +g𝑠 ) 𝑦 ) ) = ( ( 𝑓𝑥 ) ( +g𝑡 ) ( 𝑓𝑦 ) ) ∧ ( 𝑓 ‘ ( 0g𝑠 ) ) = ( 0g𝑡 ) ) } )

Detailed syntax breakdown

Step Hyp Ref Expression
0 cmhm MndHom
1 vs 𝑠
2 cmnd Mnd
3 vt 𝑡
4 vf 𝑓
5 cbs Base
6 3 cv 𝑡
7 6 5 cfv ( Base ‘ 𝑡 )
8 cmap m
9 1 cv 𝑠
10 9 5 cfv ( Base ‘ 𝑠 )
11 7 10 8 co ( ( Base ‘ 𝑡 ) ↑m ( Base ‘ 𝑠 ) )
12 vx 𝑥
13 vy 𝑦
14 4 cv 𝑓
15 12 cv 𝑥
16 cplusg +g
17 9 16 cfv ( +g𝑠 )
18 13 cv 𝑦
19 15 18 17 co ( 𝑥 ( +g𝑠 ) 𝑦 )
20 19 14 cfv ( 𝑓 ‘ ( 𝑥 ( +g𝑠 ) 𝑦 ) )
21 15 14 cfv ( 𝑓𝑥 )
22 6 16 cfv ( +g𝑡 )
23 18 14 cfv ( 𝑓𝑦 )
24 21 23 22 co ( ( 𝑓𝑥 ) ( +g𝑡 ) ( 𝑓𝑦 ) )
25 20 24 wceq ( 𝑓 ‘ ( 𝑥 ( +g𝑠 ) 𝑦 ) ) = ( ( 𝑓𝑥 ) ( +g𝑡 ) ( 𝑓𝑦 ) )
26 25 13 10 wral 𝑦 ∈ ( Base ‘ 𝑠 ) ( 𝑓 ‘ ( 𝑥 ( +g𝑠 ) 𝑦 ) ) = ( ( 𝑓𝑥 ) ( +g𝑡 ) ( 𝑓𝑦 ) )
27 26 12 10 wral 𝑥 ∈ ( Base ‘ 𝑠 ) ∀ 𝑦 ∈ ( Base ‘ 𝑠 ) ( 𝑓 ‘ ( 𝑥 ( +g𝑠 ) 𝑦 ) ) = ( ( 𝑓𝑥 ) ( +g𝑡 ) ( 𝑓𝑦 ) )
28 c0g 0g
29 9 28 cfv ( 0g𝑠 )
30 29 14 cfv ( 𝑓 ‘ ( 0g𝑠 ) )
31 6 28 cfv ( 0g𝑡 )
32 30 31 wceq ( 𝑓 ‘ ( 0g𝑠 ) ) = ( 0g𝑡 )
33 27 32 wa ( ∀ 𝑥 ∈ ( Base ‘ 𝑠 ) ∀ 𝑦 ∈ ( Base ‘ 𝑠 ) ( 𝑓 ‘ ( 𝑥 ( +g𝑠 ) 𝑦 ) ) = ( ( 𝑓𝑥 ) ( +g𝑡 ) ( 𝑓𝑦 ) ) ∧ ( 𝑓 ‘ ( 0g𝑠 ) ) = ( 0g𝑡 ) )
34 33 4 11 crab { 𝑓 ∈ ( ( Base ‘ 𝑡 ) ↑m ( Base ‘ 𝑠 ) ) ∣ ( ∀ 𝑥 ∈ ( Base ‘ 𝑠 ) ∀ 𝑦 ∈ ( Base ‘ 𝑠 ) ( 𝑓 ‘ ( 𝑥 ( +g𝑠 ) 𝑦 ) ) = ( ( 𝑓𝑥 ) ( +g𝑡 ) ( 𝑓𝑦 ) ) ∧ ( 𝑓 ‘ ( 0g𝑠 ) ) = ( 0g𝑡 ) ) }
35 1 3 2 2 34 cmpo ( 𝑠 ∈ Mnd , 𝑡 ∈ Mnd ↦ { 𝑓 ∈ ( ( Base ‘ 𝑡 ) ↑m ( Base ‘ 𝑠 ) ) ∣ ( ∀ 𝑥 ∈ ( Base ‘ 𝑠 ) ∀ 𝑦 ∈ ( Base ‘ 𝑠 ) ( 𝑓 ‘ ( 𝑥 ( +g𝑠 ) 𝑦 ) ) = ( ( 𝑓𝑥 ) ( +g𝑡 ) ( 𝑓𝑦 ) ) ∧ ( 𝑓 ‘ ( 0g𝑠 ) ) = ( 0g𝑡 ) ) } )
36 0 35 wceq MndHom = ( 𝑠 ∈ Mnd , 𝑡 ∈ Mnd ↦ { 𝑓 ∈ ( ( Base ‘ 𝑡 ) ↑m ( Base ‘ 𝑠 ) ) ∣ ( ∀ 𝑥 ∈ ( Base ‘ 𝑠 ) ∀ 𝑦 ∈ ( Base ‘ 𝑠 ) ( 𝑓 ‘ ( 𝑥 ( +g𝑠 ) 𝑦 ) ) = ( ( 𝑓𝑥 ) ( +g𝑡 ) ( 𝑓𝑦 ) ) ∧ ( 𝑓 ‘ ( 0g𝑠 ) ) = ( 0g𝑡 ) ) } )