| ⊦ (∃ a0, x0, y, z. a ' + x = x0 + (a0 + (y + (a0 + z)))) ↔ (∃ a0, x0, y, z. x = x0 + a0 ' + y + a0 ' + z), a ∈ x |
⊦ (∃ a0, x0, y, z. a ' + x = x0 + a0 ' + y + a0 ' + z) ↔ (∃ a0, x0, y, z. x = x0 + a0 ' + y + a0 ' + z), a ∈ x
Used simplifier rules: a: ⊦ (x + y) + z = x + y + z; from specification list%c: ⊦ a + x = a ' + x; from specification list