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