| (r ' + x0).last = H[r].nxt, path(r ' + x0, H), r ∈ H ⊦ r = null, H[r].nxt ≠ null ∧ H[r].nxt ∈ H |
(r ' + (r0 + x)).last = H[r].nxt, path(r ' + (r0 + x), H), r ∈ H, ∀ r, H. (r ' + x).last = H[r].nxt ∧ path(r ' + x, H) ∧ r ∈ H → r = null ∨ H[r].nxt ≠ null ∧ H[r].nxt ∈ H ⊦ r = null, H[r].nxt ≠ null ∧ H[r].nxt ∈ H
Used simplifier rules: path-one: ⊦ path(r ', H) ↔ r ∈ H ∧ r ≠ null;%reflist freely generated by [], +;;% ⊦ x0 + [] = x0; (s)%a: ⊦ (x0 + x1) + x2 = x0 + x1 + x2; from specification list[reflist]% ⊦ r '.last = r; (s)