| ⊦ a ∈ s ↔ a = s.min ∧ s ≠ ∅, a ∈ s.butmin |
Used simplifier rules: ins-inbutmins: ⊦ a ∈ s → (a ∈ s.butmin ↔ a ≠ s.min);%Max-max: ⊦ a ∈ s → ¬ s.max < a;%Min-min: ⊦ a ∈ s → ¬ a < s.min;%min-inn: ⊦ ¬ s.min ∈ s ↔ s = ∅;%ne-01: ⊦ a ∈ s → s ≠ ∅; (forward) from specification set-basic