Metamath Proof Explorer


Theorem isubgrumgr

Description: An induced subgraph of a multigraph is a multigraph. (Contributed by AV, 15-May-2025)

Ref Expression
Hypothesis isubgrupgr.v ⊢ V = Vtx ⁡ G
Assertion isubgrumgr ⊢ G ∈ UMGraph ∧ S ⊆ V → G ISubGr S ∈ UMGraph

Proof

Step Hyp Ref Expression
1 isubgrupgr.v ⊢ V = Vtx ⁡ G
2 umgruhgr ⊢ G ∈ UMGraph → G ∈ UHGraph
3 1 isubgrsubgr ⊢ G ∈ UHGraph ∧ S ⊆ V → G ISubGr S SubGraph G
4 2 3 sylan ⊢ G ∈ UMGraph ∧ S ⊆ V → G ISubGr S SubGraph G
5 subumgr ⊢ G ∈ UMGraph ∧ G ISubGr S SubGraph G → G ISubGr S ∈ UMGraph
6 4 5 syldan ⊢ G ∈ UMGraph ∧ S ⊆ V → G ISubGr S ∈ UMGraph