| 〈build_rec#(i + 1; x1, to2)〉 (x1 = x3 ∧ to2 = to1), 〈build_rec#(i + 1; x2, to2)〉 (x2 = x1 ∧ to2 = some(t)), ∀ j0, i0, x, x0, to. i→n(j0 - i0) < i→n(i1) → (x = x0 ∧ x0 ≠ [] ∧ i0 ≤ j0 ∧ max(x0) ≤ j0 → 〈build_rec#(i0; x, to)〉 (to ≠ fail → x0 = depths(to .t, i0) + x)), x2 = d ' + y, to2 = fail, d ' + y = depths(t, i + 1) + x1, d ∈ depths(t, i + 1), max(d ' + y) ≤ i1 + i, i < d, 0 ≤ i1, x = x1, to1 ≠ fail → x = depths(to1 .t, i + 1) + x3 ⊦ 〈if to1 = fail then to0 := fail else to0 := some(Node(t, to1 .t))〉 (to0 ≠ fail → d ' + y = depths(to0 .t, i) + x3) |
〈build_rec#(i + 1; x1, to2)〉 (x1 = x3 ∧ to2 = to1), 〈build_rec#(i + 1; x2, to2)〉 (x2 = x1 ∧ to2 = some(t)), ∀ j0, i0, x, x0, to. i→n(j0 - i0) < i→n(i1) → (x = x0 ∧ x0 ≠ [] ∧ i0 ≤ j0 ∧ max(x0) ≤ j0 → 〈build_rec#(i0; x, to)〉 (to ≠ fail → x0 = depths(to .t, i0) + x)), x2 = d ' + y, to2 = fail, d ' + y = depths(t, i + 1) + x1, d ∈ depths(t, i + 1), max(d ' + y) ≤ i1 + i, i < d, 0 ≤ i1, x = x1, to1 ≠ fail → x = depths(to1 .t, i + 1) + x3, to1 = fail ⊦ 〈to0 := fail〉 (to0 ≠ fail → d ' + y = depths(to0 .t, i) + x3)
〈build_rec#(i + 1; x1, to2)〉 (x1 = x3 ∧ to2 = to1), 〈build_rec#(i + 1; x2, to2)〉 (x2 = x1 ∧ to2 = some(t)), ∀ j0, i0, x, x0, to. i→n(j0 - i0) < i→n(i1) → (x = x0 ∧ x0 ≠ [] ∧ i0 ≤ j0 ∧ max(x0) ≤ j0 → 〈build_rec#(i0; x, to)〉 (to ≠ fail → x0 = depths(to .t, i0) + x)), x2 = d ' + y, to2 = fail, d ' + y = depths(t, i + 1) + x1, d ∈ depths(t, i + 1), max(d ' + y) ≤ i1 + i, i < d, 0 ≤ i1, x = x1, to1 ≠ fail → x = depths(to1 .t, i + 1) + x3, to1 ≠ fail ⊦ 〈to0 := some(Node(t, to1 .t))〉 (to0 ≠ fail → d ' + y = depths(to0 .t, i) + x3)
[[CONCRETESIMPRULES : ()]]