| ⊦ 0 ≤ i + j ∧ 0 < j0 → 0 ≤ i * j0 + j * j0 |
0 < j0, 0 ≤ i + j, ¬ 0 ≤ i * j0 + j * j0 ⊦
| 0 < j0, 0 ≤ i + j, ¬ 0 ≤ i * j0 + j * j0 ⊦ |
i * j0 + j * j0 < j0, i * j0 + j * j0 < 0, 0 < j0, (i * j0 + j * j0) + 1 < j0, 0 ≤ i + j ⊦
Used simplifier rules: ⊦ i ≤ 0 ∧ 0 ≤ j → i ≤ j; (s) ⊦ i < 0 ∧ 0 ≤ j → i < j; (s) ⊦ i +1 = i + 1; (s) 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 forward-le-02: ⊦ j < i ∧ i ≤ 0 → j < 0; (forward) from specification int-abs forward-lsle: ⊦ i < j ∧ j ≤ j0 → i < j0; (forward) from specification int-abs trans: ⊦ i < j ∧ j < j0 → i < j0; (forward) from specification int-basic1 lf-01: ⊦ i < j ∧ j < i0 → i +1 < i0; (forward) from specification int-basic1 ⊦ i ≤ j ↔ ¬ j < i; (ss)
| i * j0 + j * j0 < j0, i * j0 + j * j0 < 0, 0 < j0, (i * j0 + j * j0) + 1 < j0, 0 ≤ i + j ⊦ |
⊦ (i + i0) * j = i * j + i0 * j
(i + j) * j0 + 1 < j0, 0 < j0, (i + j) * j0 < 0, (i + j) * j0 < j0, 0 ≤ i + j ⊦
Used terms: j, j0, i
| ⊦ (i + i0) * j = i * j + i0 * j |
| (i + j) * j0 + 1 < j0, 0 < j0, (i + j) * j0 < 0, (i + j) * j0 < j0, 0 ≤ i + j ⊦ |
⊦ 0 < i → (i * j < 0 ↔ j < 0)
Used simplifier rules: zero-left: ⊦ 0 * i = 0; associativity: ⊦ i * j * j0 = (i * j) * j0; commutativity: ⊦ i * j = j * i; ⊦ i < j → ¬ j < i; (s) ⊦ i < j ↔ ¬ j ≤ i; (ss) ⊦ i ≤ j → (j ≤ i ↔ i = j); (s) lf-01: ⊦ i < j ∧ j < i0 → i +1 < i0; (forward) from specification int-basic1 trans: ⊦ i < j ∧ j < j0 → i < j0; (forward) from specification int-basic1 lf-02: ⊦ i < j ∧ j = i0 → i < i0; (forward) from specification int-basic1 forward-lsle: ⊦ i < j ∧ j ≤ j0 → i < j0; (forward) from specification int-abs forward-le-01: ⊦ i ≤ j ∧ 0 ≤ i → 0 ≤ j; (forward) from specification int-abs Used terms: j0, i + j
| ⊦ 0 < i → (i * j < 0 ↔ j < 0) |
The following image shows the proof tree of sequent calculus. The proved goal is at the bottom. You can click on the nodes to view additional rules. See here for details on colors in a proof tree.