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