| ∀ 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 → (∀ t, x1. x0 ≠ depths(t, i0) + x1))), x = x0, x0 ≠ [], max(x0) ≤ i1 + i, 0 ≤ i1, h0 = head(x), h0 < i, ¬ (fail = fail → (∀ t, x1. x0 ≠ depths(t, i) + x1)) ⊦ |
∀ 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 → (∀ t, x1. x0 ≠ depths(t, i0) + x1))), depths(t, i) + x1 ≠ [], max(depths(t, i) + x1) ≤ i1 + i, 0 ≤ i1, head(depths(t, i) + x1) < i ⊦
[[CONCRETESIMPRULES : ()]]