| unique_al(ax + p ' + ay) ⊦ unique_al(ax + ay) |
unique_al(ax + p ' + ay) ⊦ ax + ay = [], ¬ (ax + ay).head.1 ∈ (ax + ay).tail ∧ unique_al((ax + ay).tail)
Used simplifier rules: k-unique-r: ⊦ unique_al(ay) ↔ ay = [] ∨ ¬ ay.head.1 ∈ ay.tail ∧ unique_al(ay.tail);