| path(r ' + x, H) ⊦ r = null, x = [], ∃ n. reachable-n(H, n, r, (r ' + x).last) |
path(r ' + x, H) ⊦ r = null, x = [], ∃ n. reachable-n(H, n, r, x.last)
Used simplifier rules: a: ⊦ (x0 + x1) + x2 = x0 + x1 + x2; from specification list[reflist]% ⊦ x0 ≠ [] → (x1 + x0).last = x0.last; (s)