| ⊦ a0 = b, (a0 ∈ st -- a -- b ↔ a0 ∈ st -- b -- a) ∧ (st -- a -- b)[a0] = (st -- b -- a)[a0] |
⊦ a0 = b, (a0 ∈ st -- a ↔ a0 ∈ st -- b -- a) ∧ (st -- a)[a0] = (st -- b -- a)[a0]
Used simplifier rules: Del-in: ⊦ a ∈ st -- b ↔ a ≠ b ∧ a ∈ st;%Del-at-strong: a ≠ b ⊦ (st -- b)[a] = st[a];