| i < 0 ⊦ gcd(abs(i) - abs(i0), abs(i)) = gcd(abs(i) - abs(i0), abs(i0)), abs(i) < i0, i0 < 0, 0 < i ∧ i < i0 + i, 0 < abs(i) - abs(i0) ∧ abs(i) - abs(i0) < abs(i) |
i < 0 ⊦ gcd(abs(i) - abs(i0), abs(i)) = gcd(abs(i) - abs(i0), abs(i0)), i0 < 0, abs(i) < i0, abs(i) - abs(i0) < abs(i), 0 < i ∧ i < i0 + i
Used simplifier rules: gcd-neg: ⊦ gcd(~ i, j) = gcd(i, j);%gcd-com: ⊦ gcd(i, j) = gcd(j, i);%gcd-zero-04: ⊦ gcd(i, 0) = abs(i);% ⊦ i < 0 → abs(i) = ~ i; (s)% ⊦ ¬ j < 0 → abs(j) = j; (s)% ⊦ ~ i - j = ~(i + j); (s)% ⊦ 0 < ~ i ↔ i < 0; (s)% ⊦ i < j ↔ ¬ j ≤ i; (ss)% ⊦ ~ i < j ↔ 0 < j + i; (s)%add-c: ⊦ i + j = j + i; from specification int-basic2% ⊦ i ≤ j → (j ≤ i ↔ i = j); (s)% ⊦ i < 0 ∧ 0 ≤ j → i < j; (s)%forward-le-04: ⊦ j ≤ i ∧ i ≤ 0 → j ≤ 0; (forward) from specification int-abs%forward-le-01: ⊦ i ≤ j ∧ 0 ≤ i → 0 ≤ j; (forward) from specification int-abs%forward-lsle: ⊦ i < j ∧ j ≤ j0 → i < j0; (forward) from specification int-abs% ⊦ 0 ≤ i → abs(i) = i; (s)% ⊦ ~ i = j ↔ i + j = 0; (s)