| ⊦ 0 ≤ i ∧ 0 ≤ j ∧ 0 ≤ i0 ∧ 0 ≤ j0 → (((i + j) * (i + j + 1)) / 2 + j = ((i0 + j0) * (i0 + j0 + 1)) / 2 + j0 ↔ i = i0 ∧ j = j0) |
((i + j) * (i + j + 1)) / 2 + j = ((i0 + j0) * (i0 + j0 + 1)) / 2 + j0, 0 ≤ i, 0 ≤ j, 0 ≤ i0, 0 ≤ j0 ⊦ i = i0 ∧ j = j0
Used simplifier rules: forward-le-01: ⊦ i ≤ j ∧ 0 ≤ i → 0 ≤ j; (forward) 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