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