| ⊦ a ' + x = y + b ' + z ∧ a ≠ b → (∃ y0. y = a ' + y0) |
a ' + x = y + b ' + z, a ∈ y ⊦ a = b, ∃ y0. y = a ' + y0
Used simplifier rules: in-14: ⊦ a ' + x = y → a ∈ y;%a: ⊦ (x + y) + z = x + y + z;%in-append: ⊦ a ∈ x + y ↔ ¬ ¬(a ∈ x ∨ a ∈ y);%in-01: ⊦ a ≠ b → (a ∈ b ' + x ↔ a ∈ x);%inapp-02: ⊦ ¬ a ∈ y → (y + c ' + z = a ' + z0 ↔ y = [] ∧ c = a ∧ z = z0);