| ∀ a, y. # rmdup(x0 + a ' + y) = # rmdup(x0 + y) + 1 ∨ a ∈ x0 ∨ a ∈ y ⊦ #(a0 ' + rmdup(x0 + a ' + y)) = # (a0 ∈ x0 ∨ a0 ∈ y ⊃ rmdup(x0 + y);a0 ' + rmdup(x0 + y)) + 1, a = a0, a ∈ x0, a ∈ y, a0 ∈ x0, a0 ∈ y |
∀ a, y. # rmdup(x0 + a ' + y) = # rmdup(x0 + y) + 1 ∨ a ∈ x0 ∨ a ∈ y ⊦ # rmdup(x0 + a ' + y) = # rmdup(x0 + y) + 1, a = a0, a0 ∈ y, a0 ∈ x0, a ∈ y, a ∈ x0
Used simplifier rules: n < n0 ⊦ m + (* n) = m0 + (* n0) ↔ m = m0 + (n0 - n); (s)%c: ⊦ m + n = n + m; from specification nat-basic%a: ⊦ (m + n0) + n1 = m + n0 + n1; from specification nat-basic%a: ⊦ (x + y) + z = x + y + z; from specification list% ⊦ # a ' = 0 +1; (s)% ⊦ #(x + y) = # x + # y; (s)