| a < b ⊦ (∅ ++ a ++ b).butmin = ∅ ++ b, b < a |
⊦ s ≠ ∅ → s -- s.min = s.butmin
Used simplifier rules: min-two: ⊦ a < b → (∅ ++ a ++ b).min = a;% ⊦ (s ++ a ++ b) -- a = (s ++ b) -- a; (s)% ⊦ s -- a = s ↔ ¬ a ∈ s; (s)% ⊦ a ∈ ∅ ++ b ↔ a = b; (s)% ⊦ ∅ ≠ s ++ a; (s) Used terms: ∅ ++ a ++ b