| ∀ j. 0 ≤ i0 ∧ 0 ≤ j → i→n(i0) + i→n(j) = i→n(i0 + j), 0 ≤ i0 -1, 0 ≤ j ⊦ i→n(i0 -1) + i→n(j) = i→n(i0 -1 + j) |
0 ≤ j, 0 < i0, ∀ j. 0 ≤ i0 ∧ 0 ≤ j → i→n(i0) + i→n(j) = i→n(i0 + j) ⊦ i→n(i0 - 1) + i→n(j) = i→n(j + i0 - 1)
Used simplifier rules: forward-le-01: ⊦ i ≤ j ∧ 0 ≤ i → 0 ≤ j; (forward) from specification int-abs%forward-le-05: ⊦ i < j ∧ 0 ≤ i → 0 < j; (forward) from specification int-abs%leone: ⊦ 1 ≤ i ↔ 0 < i; from specification int-abs%sub-le-01: ⊦ i ≤ j - i0 ↔ i + i0 ≤ j; from specification int-abs%add-c: ⊦ i + j = j + i; from specification int-basic2%add-a: ⊦ i + j + i0 = (i + j) + i0; from specification int-basic2%sub-add-01: ⊦ i + (j - i0) = i + j - i0; from specification int-abs%sub-pred: ⊦ i -1 = i - 1; from specification int-abs