| ⊦ a0 = a, a = b, (a0 ∈ st[b, d0][a, d] ↔ a0 ∈ st[a, d][b, d0]) ∧ st[b, d0][a, d][a0] = st[a, d][b, d0][a0] |
⊦ a0 = a, a = b, (a0 ∈ st[b, d0] ↔ a0 ∈ st[a, d][b, d0]) ∧ st[b, d0][a0] = st[a, d][b, d0][a0]
Used simplifier rules: in-neq: ⊦ a ≠ b → (a ∈ st[b, d] ↔ a ∈ st);%At-other: ⊦ a ≠ b → st[b, d][a] = st[a];