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