Description: Reverse closure of the "is locally isomorphic to" relation for graphs. (Contributed by AV, 9-Jun-2025)
Ref | Expression | ||
---|---|---|---|
Assertion | grlicrcl | ⊢ ( 𝐺 ≃𝑙𝑔𝑟 𝑆 → ( 𝐺 ∈ V ∧ 𝑆 ∈ V ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | brgrlic | ⊢ ( 𝐺 ≃𝑙𝑔𝑟 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 | ⊢ ( 𝐺 ≃𝑙𝑔𝑟 𝑆 → ( 𝐺 ∈ V ∧ 𝑆 ∈ V ) ) |