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 e. USGraph /\ S C_ V ) -> ( G ISubGr S ) e. USGraph )

Proof

Step Hyp Ref Expression
1 isubgrupgr.v
 |-  V = ( Vtx ` G )
2 usgruhgr
 |-  ( G e. USGraph -> G e. UHGraph )
3 1 isubgrsubgr
 |-  ( ( G e. UHGraph /\ S C_ V ) -> ( G ISubGr S ) SubGraph G )
4 2 3 sylan
 |-  ( ( G e. USGraph /\ S C_ V ) -> ( G ISubGr S ) SubGraph G )
5 subusgr
 |-  ( ( G e. USGraph /\ ( G ISubGr S ) SubGraph G ) -> ( G ISubGr S ) e. USGraph )
6 4 5 syldan
 |-  ( ( G e. USGraph /\ S C_ V ) -> ( G ISubGr S ) e. USGraph )