| a2 ∈ st0[a, d][a0, d0], a2 ∈ st[a, d][a0, d0], st ⊆ st0 ⊦ st[a, d][a0, d0][a2] = st0[a, d][a0, d0][a2], a2 = a1, a2 = a0 |
a2 ∈ st[a, d], a2 ∈ st0[a, d], st ⊆ st0 ⊦ st[a, d][a2] = st0[a, d][a2], a2 = a0, a2 = a1
Used simplifier rules: At-other: ⊦ a ≠ b → st[b, d][a] = st[a];%In-insert: ⊦ a ∈ st[b, d] ↔ a = b ∨ a ∈ st;