inv(st[m]), @(m, m0, 0) ∈ as, @(m, m0, 0) ∈ st, m ∈ st, as ⊆ dom nodes(st) ⊦ # as = 0, as = ∅
Used simplifier rules: ⊦ ¬ n ∈ st → ¬ @(n, n0, n1) ∈ st; (s)