a ∈ st, ∀ a0, d, st0. st ≠ st0[a0, d] ∨ a0 ∈ st0 ⊦
Used simplifier rules: In-empty: ⊦ ¬ a ∈ ∅;%notmemlookup: ⊦ ¬ a ∈ st → st[a] = (∅)[a];