| ⊦ i | j ∧ j | i ∧ i ≤ 0 ∧ j ≤ 0 → (i = j ↔ true) |
¬(i = j ↔ true), i | j, j | i, i ≤ 0, j ≤ 0 ⊦
| ¬(i = j ↔ true), i | j, j | i, i ≤ 0, j ≤ 0 ⊦ |
i ≠ j, j | i, i | j, j ≤ 0, i ≤ 0 ⊦
Used simplifier rules: forward-le-04: ⊦ j ≤ i ∧ i ≤ 0 → j ≤ 0; (forward) from specification int-abs
| i ≠ j, j | i, i | j, j ≤ 0, i ≤ 0 ⊦ |
⊦ i | j ↔ (∃ i0. i * i0 = j)
i ≠ j, j | i, i ≤ 0, j ≤ 0, ∃ i0. i * i0 = j ⊦
Used terms: j, i
| ⊦ i | j ↔ (∃ i0. i * i0 = j) |
| i ≠ j, j | i, i ≤ 0, j ≤ 0, ∃ i0. i * i0 = j ⊦ |
i ≠ 0, i0 ≠ 1, i < 0, i * i0 | i, 0 ≤ i0 ⊦
Used simplifier rules: ⊦ i < 0 ∧ 0 ≤ j → i < j; (s) 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 forward-le-01: ⊦ i ≤ j ∧ 0 ≤ i → 0 ≤ j; (forward) from specification int-abs commutativity: ⊦ i * j = j * i; from specification int-mult associativity: ⊦ i * j * j0 = (i * j) * j0; from specification int-mult ⊦ i < 0 → (i * j ≤ 0 ↔ 0 ≤ j); (s) ⊦ i ≠ j → (i ≤ j ↔ i < j); (s) ⊦ i * j = i ↔ i = 0 ∨ j = 1; (ws)
| i ≠ 0, i0 ≠ 1, i < 0, i * i0 | i, 0 ≤ i0 ⊦ |
⊦ i | j ↔ (∃ i0. i * i0 = j)
Used simplifier rules: ⊦ i ≠ 0 → (i * j = i ↔ j = 1); (s) ⊦ i * j = 1 ↔ abs(i) = 1 ∧ i = j; (ws) associativity: ⊦ i * j * j0 = (i * j) * j0; from specification int-mult commutativity: ⊦ i * j = j * i; from specification int-mult ⊦ 0 ≤ i → abs(i) = i; (s) Used terms: i, i * i0
| ⊦ i | j ↔ (∃ i0. i * i0 = j) |
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.