Metamath Proof Explorer


Theorem grlicrcl

Description: Reverse closure of the "is locally isomorphic to" relation for graphs. (Contributed by AV, 9-Jun-2025)

Ref Expression
Assertion grlicrcl ( 𝐺𝑙𝑔𝑟 𝑆 → ( 𝐺 ∈ V ∧ 𝑆 ∈ V ) )

Proof

Step Hyp Ref Expression
1 brgrlic ( 𝐺𝑙𝑔𝑟 𝑆 ↔ ( 𝐺 GraphLocIso 𝑆 ) ≠ ∅ )
2 grlimdmrel Rel dom GraphLocIso
3 2 ovprc ( ¬ ( 𝐺 ∈ V ∧ 𝑆 ∈ V ) → ( 𝐺 GraphLocIso 𝑆 ) = ∅ )
4 3 necon1ai ( ( 𝐺 GraphLocIso 𝑆 ) ≠ ∅ → ( 𝐺 ∈ V ∧ 𝑆 ∈ V ) )
5 1 4 sylbi ( 𝐺𝑙𝑔𝑟 𝑆 → ( 𝐺 ∈ V ∧ 𝑆 ∈ V ) )