| ∀ a, x0, y, y0. (a ' + x0) + y = z0 + y0 ∧ # x0 + 1 = # z0 ∧ (∀ z, y, y0. # x0 = # z ∧ x0 + y = z + y0 → x0 = z ∧ y = y0) ∧ (a ∈ z0 ∨ a ∈ y0) → a ' + x0 = z0 ∧ y = y0, (a ' + x0) + y = (a0 + z0) + y0, # x0 + 1 = #(a0 + z0), ∀ z, y, y0. # x0 = # z ∧ x0 + y = z + y0 → x0 = z ∧ y = y0, a ∈ a0 + z0 ∨ a ∈ y0 ⊦ a ' + x0 = a0 + z0 ∧ y = y0 |
# x0 = # z0, x0 + y = z0 + y0, ∀ z, y, y0. # z0 = # z ∧ x0 + y = z + y0 → x0 = z ∧ y = y0, ∀ a, x0, y, y0. (a ' + x0) + y = z0 + y0 ∧ # x0 + 1 = # z0 ∧ (∀ z, y, y0. # x0 = # z ∧ x0 + y = z + y0 → x0 = z ∧ y = y0) ∧ (a ∈ z0 ∨ a ∈ y0) → a ' + x0 = z0 ∧ y = y0 ⊦ x0 = z0 ∧ y = y0
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;%len-05: ⊦ #(a ' + x) = (# x)+1;%in-rec: ⊦ a ∈ b ' + x ↔ ¬ ¬(a = b ∨ a ∈ x);%c: ⊦ m + n = n + m; from specification nat-basic2%a: ⊦ (m + n0) + n1 = m + n0 + n1; from specification nat-basic2%eq-01: ⊦ m + n = m + n0 ↔ n = n0; from specification nat-basic2%succ: ⊦ m +1 = m + 1; from specification nat-basic2