Metamath Proof Explorer


Theorem nghmghm

Description: A normed group homomorphism is a group homomorphism. (Contributed by Mario Carneiro, 18-Oct-2015)

Ref Expression
Assertion nghmghm ⊢ F ∈ S NGHom T → F ∈ S GrpHom T

Proof

Step Hyp Ref Expression
1 eqid ⊢ S normOp T = S normOp T
2 1 isnghm ⊢ F ∈ S NGHom T ↔ S ∈ NrmGrp ∧ T ∈ NrmGrp ∧ F ∈ S GrpHom T ∧ S normOp T ⁡ F ∈ ℝ
3 2 simprbi ⊢ F ∈ S NGHom T → F ∈ S GrpHom T ∧ S normOp T ⁡ F ∈ ℝ
4 3 simpld ⊢ F ∈ S NGHom T → F ∈ S GrpHom T