| (∀ a0. (a0 ∈ st ↔ a0 ∈ st0 -- a) ∧ (a0 ∈ st → st[a0] = (st0 -- a)[a0])) ∧ a ∈ st0 ∧ st0[a] = d ⊦ ∀ a0. (a0 ∈ st[a, d] ↔ a0 ∈ st0) ∧ (a0 ∈ st[a, d] → st[a, d][a0] = st0[a0]), a ∈ st |
a ∈ st0, ∀ a0. (a0 ∈ st ↔ a0 ∈ st0 -- a) ∧ (a0 ∈ st → st[a0] = (st0 -- a)[a0]) ⊦ a ∈ st, (a0 ∈ st[a, st0[a]] ↔ a0 ∈ st0) ∧ (a0 ∈ st[a, st0[a]] → st[a, st0[a]][a0] = st0[a0])