Metamath Proof Explorer


Theorem isubgrusgr

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

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

Proof

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