| b ' + x = y + a ' + z ⊦ y = [], a = b, x = y.rest + a ' + z, ∃ y, z. x = y + a ' + z |
Used simplifier rules: c: ⊦ a + x = a ' + x;%a: ⊦ (x + y) + z = x + y + z;%c-06: ⊦ a ' + x = b ' + y ↔ a = b ∧ x = y;%x ≠ [] ⊦ a = x.first ∧ y = x.rest ↔ x = a + y; (elim) Used terms: y, a0, y0