| mkDecimal(i, j) - mkDecimal(j1, abs(j0) - 1) = mkDecimal((i * 10 ^ (abs(j0) - 1) - j1 * 10 ^ abs(j)) * 10, abs(abs(j) + abs(j0) - 1) + 1), ∀ i1, i2, j, j0. i→n(i1) + i→n(i2) < i→n(i) + i→n(j1 * 10) → true → mkDecimal(i1, j) - mkDecimal(i2, j0) = mkDecimal(i1 * 10 ^ abs(j0) - i2 * 10 ^ abs(j), abs(j) + abs(j0)) ⊦ j0 = 0, mkDecimal((i * 10 ^ (abs(j0) - 1) - j1 * 10 ^ abs(j)) * 10, abs(abs(j) + abs(j0) - 1) + 1) = mkDecimal(i * 10 ^ abs(j0) - (j1 * 10) * 10 ^ abs(j), abs(j) + abs(j0)), i % 10 = 0 ∧ j ≠ 0 |
⊦ ¬ j < 0 → abs(j) = j
¬ ¬ abs(j) + abs(j0) - 1 < 0, mkDecimal(i, j) - mkDecimal(j1, abs(j0) - 1) = mkDecimal((i * 10 ^ (abs(j0) - 1) - j1 * 10 ^ abs(j)) * 10, abs(abs(j) + abs(j0) - 1) + 1), ∀ i1, i2, j, j0. i→n(i1) + i→n(i2) < i→n(i) + i→n(j1 * 10) → true → mkDecimal(i1, j) - mkDecimal(i2, j0) = mkDecimal(i1 * 10 ^ abs(j0) - i2 * 10 ^ abs(j), abs(j) + abs(j0)) ⊦ j0 = 0, mkDecimal((i * 10 ^ (abs(j0) - 1) - j1 * 10 ^ abs(j)) * 10, abs(abs(j) + abs(j0) - 1) + 1) = mkDecimal(i * 10 ^ abs(j0) - (j1 * 10) * 10 ^ abs(j), abs(j) + abs(j0)), i % 10 = 0 ∧ j ≠ 0
¬ abs(j) + abs(j0) - 1 < 0, mkDecimal(i, j) - mkDecimal(j1, abs(j0) - 1) = mkDecimal((i * 10 ^ (abs(j0) - 1) - j1 * 10 ^ abs(j)) * 10, (abs(j) + abs(j0) - 1) + 1), ∀ i1, i2, j, j0. i→n(i1) + i→n(i2) < i→n(i) + i→n(j1 * 10) → true → mkDecimal(i1, j) - mkDecimal(i2, j0) = mkDecimal(i1 * 10 ^ abs(j0) - i2 * 10 ^ abs(j), abs(j) + abs(j0)) ⊦ j0 = 0, mkDecimal((i * 10 ^ (abs(j0) - 1) - j1 * 10 ^ abs(j)) * 10, (abs(j) + abs(j0) - 1) + 1) = mkDecimal(i * 10 ^ abs(j0) - (j1 * 10) * 10 ^ abs(j), abs(j) + abs(j0)), i % 10 = 0 ∧ j ≠ 0
Used terms: abs(j) + abs(j0) - 1