a ∈ s, ∀ b. b ∈ s → ¬ b < a ⊦ a = s.min
Used simplifier rules: ⊦ a ∈ s ++ b ↔ a = b ∨ a ∈ s; (s)% ⊦ a ∈ ∅ ++ b ↔ a = b; (s)% ⊦ ¬ a < a; (s) Used terms: a, ∅ ++ a ++ b