| y + c ' + z = a ' + z0, a = c ∨ a ∈ z ⊦ a ∈ y, y = [] ∧ c = a ∧ z = z0 |
Used simplifier rules: Nil: ⊦ [] + x = x;%a: ⊦ (x + y) + z = x + y + z;%c-06: ⊦ a ' + x = b ' + y ↔ a = b ∧ x = y;%in-empty: ⊦ ¬ a ∈ [];%c: ⊦ a + x = a ' + x;%a: ⊦ (x + y) + z = x + y + z;%c-06: ⊦ a ' + x = b ' + y ↔ a = b ∧ x = y;%in-06: ⊦ ¬ a ∈ b ' + x ↔ a ≠ b ∧ ¬ a ∈ x;%list freely generated by [], +;;