| ⊦ adr ∈ st, ∀ adr0. adr0 ∈ (as ++ adr) \ dom nodes(st) ↔ adr0 ∈ (as \ dom nodes(st)) ++ adr |
⊦ adr0 ∈ (as ++ adr) \ dom nodes(st) ↔ adr0 = adr ∨ adr0 ∈ as \ dom nodes(st), adr ∈ st
Used simplifier rules: ⊦ adr ∈ as ++ adr0 ↔ adr = adr0 ∨ adr ∈ as; (s)