| ¬ i + 1 ≤ i2 + 1, i1 + i = i2 + 1, 0 ≤ i1, ∀ j0, i0. i→n(j0 - i0) < i→n(i1) → i0 ≤ j0 → count-i2j(i0, j0) = i0 ' + count-i2j(i0 + 1, j0) ⊦ count-i2j(i, i2) + (i2 + 1)' = i ' + count-i2j(i + 1, i2 + 1) |
i1 + i = i2 + 1, 0 ≤ i1, i2 < i, ∀ j0, i0. i→n(j0 - i0) < i→n(i1) → i0 ≤ j0 → count-i2j(i0, j0) = i0 ' + count-i2j(i0 + 1, j0) ⊦ (i2 + 1)' = i ' + count-i2j(i + 1, i2 + 1)
Used simplifier rules: counti2j-empty: ⊦ j < i → count-i2j(i, j) = [];%a: ⊦ (ints + ints0) + ints1 = ints + ints0 + ints1; from specification list[intlista]%Nil: ⊦ [] + ints = ints; from specification list[intlista]%add-c: ⊦ i + j = j + i; from specification int-basic2%add-a: ⊦ i + j + i0 = (i + j) + i0; from specification int-basic2%lels-01: ⊦ ¬ i ≤ j ↔ j < i; from specification int-abs%le-add: ⊦ i + j ≤ i0 + j ↔ i ≤ i0; from specification int-abs