⊦ st1 = st2 ↔ (∀ a. (a ∈ st1 ↔ a ∈ st2) ∧ st1[a] = st2[a])
∀ a0. (a0 ∈ st[a, d] ↔ a0 ∈ st0[a, d0]) ∧ st[a, d][a0] = st0[a, d0][a0] ⊦ d = d0
Used terms: st0[a, d0], st[a, d]