| Step | Hyp | Ref
 | Expression | 
| 1 |   | id 19 | 
. 2
⊢ ((𝑀 ∈ Mnd ∧ 𝑁 ∈ Mnd) → (𝑀 ∈ Mnd ∧ 𝑁 ∈ Mnd)) | 
| 2 |   | eqid 2196 | 
. . . . . 6
⊢
(Base‘𝑁) =
(Base‘𝑁) | 
| 3 |   | 0mhm.z | 
. . . . . 6
⊢  0 =
(0g‘𝑁) | 
| 4 | 2, 3 | mndidcl 13071 | 
. . . . 5
⊢ (𝑁 ∈ Mnd → 0 ∈
(Base‘𝑁)) | 
| 5 | 4 | adantl 277 | 
. . . 4
⊢ ((𝑀 ∈ Mnd ∧ 𝑁 ∈ Mnd) → 0 ∈
(Base‘𝑁)) | 
| 6 |   | fconst6g 5456 | 
. . . 4
⊢ ( 0 ∈
(Base‘𝑁) →
(𝐵 × { 0 }):𝐵⟶(Base‘𝑁)) | 
| 7 | 5, 6 | syl 14 | 
. . 3
⊢ ((𝑀 ∈ Mnd ∧ 𝑁 ∈ Mnd) → (𝐵 × { 0 }):𝐵⟶(Base‘𝑁)) | 
| 8 |   | simpr 110 | 
. . . . . . 7
⊢ ((𝑀 ∈ Mnd ∧ 𝑁 ∈ Mnd) → 𝑁 ∈ Mnd) | 
| 9 |   | eqid 2196 | 
. . . . . . . . 9
⊢
(+g‘𝑁) = (+g‘𝑁) | 
| 10 | 2, 9, 3 | mndlid 13076 | 
. . . . . . . 8
⊢ ((𝑁 ∈ Mnd ∧ 0 ∈
(Base‘𝑁)) → (
0
(+g‘𝑁)
0 ) =
0
) | 
| 11 | 10 | eqcomd 2202 | 
. . . . . . 7
⊢ ((𝑁 ∈ Mnd ∧ 0 ∈
(Base‘𝑁)) →
0 = (
0
(+g‘𝑁)
0
)) | 
| 12 | 8, 4, 11 | syl2anc2 412 | 
. . . . . 6
⊢ ((𝑀 ∈ Mnd ∧ 𝑁 ∈ Mnd) → 0 = ( 0
(+g‘𝑁)
0
)) | 
| 13 | 12 | adantr 276 | 
. . . . 5
⊢ (((𝑀 ∈ Mnd ∧ 𝑁 ∈ Mnd) ∧ (𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐵)) → 0 = ( 0 (+g‘𝑁) 0 )) | 
| 14 |   | fn0g 13018 | 
. . . . . . . . 9
⊢
0g Fn V | 
| 15 | 8 | elexd 2776 | 
. . . . . . . . 9
⊢ ((𝑀 ∈ Mnd ∧ 𝑁 ∈ Mnd) → 𝑁 ∈ V) | 
| 16 |   | funfvex 5575 | 
. . . . . . . . . 10
⊢ ((Fun
0g ∧ 𝑁
∈ dom 0g) → (0g‘𝑁) ∈ V) | 
| 17 | 16 | funfni 5358 | 
. . . . . . . . 9
⊢
((0g Fn V ∧ 𝑁 ∈ V) → (0g‘𝑁) ∈ V) | 
| 18 | 14, 15, 17 | sylancr 414 | 
. . . . . . . 8
⊢ ((𝑀 ∈ Mnd ∧ 𝑁 ∈ Mnd) →
(0g‘𝑁)
∈ V) | 
| 19 | 3, 18 | eqeltrid 2283 | 
. . . . . . 7
⊢ ((𝑀 ∈ Mnd ∧ 𝑁 ∈ Mnd) → 0 ∈
V) | 
| 20 | 19 | adantr 276 | 
. . . . . 6
⊢ (((𝑀 ∈ Mnd ∧ 𝑁 ∈ Mnd) ∧ (𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐵)) → 0 ∈ V) | 
| 21 |   | 0mhm.b | 
. . . . . . . . 9
⊢ 𝐵 = (Base‘𝑀) | 
| 22 |   | eqid 2196 | 
. . . . . . . . 9
⊢
(+g‘𝑀) = (+g‘𝑀) | 
| 23 | 21, 22 | mndcl 13064 | 
. . . . . . . 8
⊢ ((𝑀 ∈ Mnd ∧ 𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐵) → (𝑥(+g‘𝑀)𝑦) ∈ 𝐵) | 
| 24 | 23 | 3expb 1206 | 
. . . . . . 7
⊢ ((𝑀 ∈ Mnd ∧ (𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐵)) → (𝑥(+g‘𝑀)𝑦) ∈ 𝐵) | 
| 25 | 24 | adantlr 477 | 
. . . . . 6
⊢ (((𝑀 ∈ Mnd ∧ 𝑁 ∈ Mnd) ∧ (𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐵)) → (𝑥(+g‘𝑀)𝑦) ∈ 𝐵) | 
| 26 |   | fvconst2g 5776 | 
. . . . . 6
⊢ (( 0 ∈ V
∧ (𝑥(+g‘𝑀)𝑦) ∈ 𝐵) → ((𝐵 × { 0 })‘(𝑥(+g‘𝑀)𝑦)) = 0 ) | 
| 27 | 20, 25, 26 | syl2anc 411 | 
. . . . 5
⊢ (((𝑀 ∈ Mnd ∧ 𝑁 ∈ Mnd) ∧ (𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐵)) → ((𝐵 × { 0 })‘(𝑥(+g‘𝑀)𝑦)) = 0 ) | 
| 28 |   | simprl 529 | 
. . . . . . 7
⊢ (((𝑀 ∈ Mnd ∧ 𝑁 ∈ Mnd) ∧ (𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐵)) → 𝑥 ∈ 𝐵) | 
| 29 |   | fvconst2g 5776 | 
. . . . . . 7
⊢ (( 0 ∈ V
∧ 𝑥 ∈ 𝐵) → ((𝐵 × { 0 })‘𝑥) = 0 ) | 
| 30 | 20, 28, 29 | syl2anc 411 | 
. . . . . 6
⊢ (((𝑀 ∈ Mnd ∧ 𝑁 ∈ Mnd) ∧ (𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐵)) → ((𝐵 × { 0 })‘𝑥) = 0 ) | 
| 31 |   | simprr 531 | 
. . . . . . 7
⊢ (((𝑀 ∈ Mnd ∧ 𝑁 ∈ Mnd) ∧ (𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐵)) → 𝑦 ∈ 𝐵) | 
| 32 |   | fvconst2g 5776 | 
. . . . . . 7
⊢ (( 0 ∈ V
∧ 𝑦 ∈ 𝐵) → ((𝐵 × { 0 })‘𝑦) = 0 ) | 
| 33 | 20, 31, 32 | syl2anc 411 | 
. . . . . 6
⊢ (((𝑀 ∈ Mnd ∧ 𝑁 ∈ Mnd) ∧ (𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐵)) → ((𝐵 × { 0 })‘𝑦) = 0 ) | 
| 34 | 30, 33 | oveq12d 5940 | 
. . . . 5
⊢ (((𝑀 ∈ Mnd ∧ 𝑁 ∈ Mnd) ∧ (𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐵)) → (((𝐵 × { 0 })‘𝑥)(+g‘𝑁)((𝐵 × { 0 })‘𝑦)) = ( 0 (+g‘𝑁) 0 )) | 
| 35 | 13, 27, 34 | 3eqtr4d 2239 | 
. . . 4
⊢ (((𝑀 ∈ Mnd ∧ 𝑁 ∈ Mnd) ∧ (𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐵)) → ((𝐵 × { 0 })‘(𝑥(+g‘𝑀)𝑦)) = (((𝐵 × { 0 })‘𝑥)(+g‘𝑁)((𝐵 × { 0 })‘𝑦))) | 
| 36 | 35 | ralrimivva 2579 | 
. . 3
⊢ ((𝑀 ∈ Mnd ∧ 𝑁 ∈ Mnd) →
∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 ((𝐵 × { 0 })‘(𝑥(+g‘𝑀)𝑦)) = (((𝐵 × { 0 })‘𝑥)(+g‘𝑁)((𝐵 × { 0 })‘𝑦))) | 
| 37 |   | eqid 2196 | 
. . . . . 6
⊢
(0g‘𝑀) = (0g‘𝑀) | 
| 38 | 21, 37 | mndidcl 13071 | 
. . . . 5
⊢ (𝑀 ∈ Mnd →
(0g‘𝑀)
∈ 𝐵) | 
| 39 | 38 | adantr 276 | 
. . . 4
⊢ ((𝑀 ∈ Mnd ∧ 𝑁 ∈ Mnd) →
(0g‘𝑀)
∈ 𝐵) | 
| 40 |   | fvconst2g 5776 | 
. . . 4
⊢ (( 0 ∈ V
∧ (0g‘𝑀) ∈ 𝐵) → ((𝐵 × { 0
})‘(0g‘𝑀)) = 0 ) | 
| 41 | 19, 39, 40 | syl2anc 411 | 
. . 3
⊢ ((𝑀 ∈ Mnd ∧ 𝑁 ∈ Mnd) → ((𝐵 × { 0
})‘(0g‘𝑀)) = 0 ) | 
| 42 | 7, 36, 41 | 3jca 1179 | 
. 2
⊢ ((𝑀 ∈ Mnd ∧ 𝑁 ∈ Mnd) → ((𝐵 × { 0 }):𝐵⟶(Base‘𝑁) ∧ ∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 ((𝐵 × { 0 })‘(𝑥(+g‘𝑀)𝑦)) = (((𝐵 × { 0 })‘𝑥)(+g‘𝑁)((𝐵 × { 0 })‘𝑦)) ∧ ((𝐵 × { 0
})‘(0g‘𝑀)) = 0 )) | 
| 43 | 21, 2, 22, 9, 37, 3 | ismhm 13093 | 
. 2
⊢ ((𝐵 × { 0 }) ∈ (𝑀 MndHom 𝑁) ↔ ((𝑀 ∈ Mnd ∧ 𝑁 ∈ Mnd) ∧ ((𝐵 × { 0 }):𝐵⟶(Base‘𝑁) ∧ ∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 ((𝐵 × { 0 })‘(𝑥(+g‘𝑀)𝑦)) = (((𝐵 × { 0 })‘𝑥)(+g‘𝑁)((𝐵 × { 0 })‘𝑦)) ∧ ((𝐵 × { 0
})‘(0g‘𝑀)) = 0 ))) | 
| 44 | 1, 42, 43 | sylanbrc 417 | 
1
⊢ ((𝑀 ∈ Mnd ∧ 𝑁 ∈ Mnd) → (𝐵 × { 0 }) ∈ (𝑀 MndHom 𝑁)) |