| a ' + x0 = x + b ' + y + c ' + z ⊦ # x + # z < # x0 |
a ' + x0 = x + b ' + y + c ' + z, # x0 ≤ # x + # z, a ∈ x ∨ a = b ∨ a ∈ y ∨ a = c ∨ a ∈ z ⊦
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-rec: ⊦ a ∈ b ' + x ↔ a = b ∨ a ∈ x;% ⊦ m < n ↔ ¬ n ≤ m; (ss)