⊦ as = as0 ↔ (∀ adr. adr ∈ as ↔ adr ∈ as0)
as ⊆ dom nodes(st) ⊦ #(as | n) = 0, n ∈ st, ∀ adr. adr ∈ as | n ↔ adr ∈ ∅
Used terms: ∅, as | n