Metamath Proof Explorer


Theorem 0ghm

Description: The constant zero linear function between two groups. (Contributed by Stefan O'Rear, 5-Sep-2015)

Ref Expression
Hypotheses 0ghm.z ⊢ 0 ˙ = 0 N
0ghm.b ⊢ B = Base M
Assertion 0ghm ⊢ M ∈ Grp ∧ N ∈ Grp → B × 0 ˙ ∈ M GrpHom N

Proof

Step Hyp Ref Expression
1 0ghm.z ⊢ 0 ˙ = 0 N
2 0ghm.b ⊢ B = Base M
3 grpmnd ⊢ M ∈ Grp → M ∈ Mnd
4 grpmnd ⊢ N ∈ Grp → N ∈ Mnd
5 1 2 0mhm ⊢ M ∈ Mnd ∧ N ∈ Mnd → B × 0 ˙ ∈ M MndHom N
6 3 4 5 syl2an ⊢ M ∈ Grp ∧ N ∈ Grp → B × 0 ˙ ∈ M MndHom N
7 ghmmhmb ⊢ M ∈ Grp ∧ N ∈ Grp → M GrpHom N = M MndHom N
8 6 7 eleqtrrd ⊢ M ∈ Grp ∧ N ∈ Grp → B × 0 ˙ ∈ M GrpHom N