| ⊦ (a ∈ st \ s ∧ ¬ a ∈ s0 ↔ a ∈ (st \ s0) \ s) ∧ (a ∈ st \ s ∧ ¬ a ∈ s0 → ((st \ s) \ s0)[a] = ((st \ s0) \ s)[a]) |
⊦ (a ∈ st \ s ∧ ¬ a ∈ s0 ↔ a ∈ (st \ s0) \ s) ∧ (a ∈ st \ s ∧ ¬ a ∈ s0 → (st \ s)[a] = ((st \ s0) \ s)[a])
Used simplifier rules: Diff-get: ⊦ ¬ a ∈ s → (st \ s)[a] = st[a];