| ∀ a, b, x, a0, c. a ' + b ' = x + a0 ' + c ' + y0 ∧ (a ∈ x ∨ a = a0 ∨ a = c ∨ a ∈ y0) → x = [] ∧ y0 = [] ∧ a = a0 ∧ b = c, a ' + b ' = x + a0 ' + c ' + (a1 + y0), a ∈ x ∨ a = a0 ∨ a = c ∨ a ∈ a1 + y0 ⊦ x = [] ∧ a1 + y0 = [] ∧ a = a0 ∧ b = c |
a ' + b ' = x + a0 ' + c ' + a1 ' + y0, a ∈ x, ∀ a, b, x, a0, c. a ' + b ' = x + a0 ' + c ' + y0 ∧ (a ∈ x ∨ a = a0 ∨ a = c ∨ a ∈ y0) → x = [] ∧ y0 = [] ∧ a = a0 ∧ b = c ⊦
Used simplifier rules: c: ⊦ a + x = a ' + x;%a: ⊦ (x + y) + z = x + y + z;%in-rec: ⊦ a ∈ b ' + x ↔ ¬ ¬(a = b ∨ a ∈ x);%e-01: ⊦ a ' + x ≠ [];%in-14: ⊦ a ' + x = y → a ∈ y;%in-15: ⊦ x + a ' = y → a ∈ y;%in-append: ⊦ a ∈ x + y ↔ ¬ ¬(a ∈ x ∨ a ∈ y);%inapp-02: ⊦ ¬ a ∈ y → (y + c ' + z = a ' + z0 ↔ y = [] ∧ c = a ∧ z = z0);%c-03: ⊦ a ' = b ' + x ↔ a = b ∧ x = [];%in-16: ⊦ x + a ' = y + b ' + z ∧ a ≠ b → a ∈ z;