| a ∈ s, a ∈ st ⊦ s = ∅, (st \ (dom st \ s))[a] = st[a], # s = 0 |
⊦ ¬ a ∈ s → (st \ s)[a] = st[a]
Used simplifier rules: Diff-mems-get: ⊦ a ∈ s → (st \ s)[a] = (∅)[a];%Dom: ⊦ a ∈ dom st ↔ a ∈ st;%Difference: ⊦ a ∈ s1 \ s2 ↔ a ∈ s1 ∧ ¬ a ∈ s2; from specification set-union Used terms: a, dom st \ s, st