Metamath Proof Explorer


Theorem grilcbri

Description: Implications of two graphs being locally isomorphic. (Contributed by AV, 9-Jun-2025)

Ref Expression
Hypotheses dfgrlic2.v
|- V = ( Vtx ` G )
dfgrlic2.w
|- W = ( Vtx ` H )
Assertion grilcbri
|- ( G ~=lgr H -> E. f ( f : V -1-1-onto-> W /\ A. v e. V ( G ISubGr ( G ClNeighbVtx v ) ) ~=gr ( H ISubGr ( H ClNeighbVtx ( f ` v ) ) ) ) )

Proof

Step Hyp Ref Expression
1 dfgrlic2.v
 |-  V = ( Vtx ` G )
2 dfgrlic2.w
 |-  W = ( Vtx ` H )
3 grlicrcl
 |-  ( G ~=lgr H -> ( G e. _V /\ H e. _V ) )
4 1 2 dfgrlic2
 |-  ( ( G e. _V /\ H e. _V ) -> ( G ~=lgr H <-> E. f ( f : V -1-1-onto-> W /\ A. v e. V ( G ISubGr ( G ClNeighbVtx v ) ) ~=gr ( H ISubGr ( H ClNeighbVtx ( f ` v ) ) ) ) ) )
5 3 4 syl
 |-  ( G ~=lgr H -> ( G ~=lgr H <-> E. f ( f : V -1-1-onto-> W /\ A. v e. V ( G ISubGr ( G ClNeighbVtx v ) ) ~=gr ( H ISubGr ( H ClNeighbVtx ( f ` v ) ) ) ) ) )
6 5 ibi
 |-  ( G ~=lgr H -> E. f ( f : V -1-1-onto-> W /\ A. v e. V ( G ISubGr ( G ClNeighbVtx v ) ) ~=gr ( H ISubGr ( H ClNeighbVtx ( f ` v ) ) ) ) )