| (H[r].nxt ' + x).last = (H[r].nxt ' + x0).last, path(H[r].nxt ' + x0, H), r ∈ H, path(H[r].nxt ' + x, H), ∀ r, H. path(r ' + x0, H) → (∃ x1. path(r ' + x1, H) ∧ (r ' + x1).last = (r ' + x0).last ∧ ¬ r ∈ x1 ∧ ¬ dups(x1)) ⊦ r = null, dups(x), H[r].nxt ∈ x, path(r ' + H[r].nxt ' + x, H) ∧ (r ' + H[r].nxt ' + x).last = (H[r].nxt ' + x0).last ∧ ¬ r ∈ H[r].nxt ' + x ∧ ¬ dups(H[r].nxt ' + x), ∃ x. path(r ' + x, H) ∧ (r ' + x).last = (H[r].nxt ' + x0).last ∧ ¬ r ∈ x ∧ ¬ dups(x) |
(H[r].nxt ' + x).last = (H[r].nxt ' + x0).last, path(H[r].nxt ' + x0, H), r ∈ H, path(H[r].nxt ' + x, H), ∀ r, H. path(r ' + x0, H) → (∃ x1. path(r ' + x1, H) ∧ (r ' + x1).last = (r ' + x0).last ∧ ¬ r ∈ x1 ∧ ¬ dups(x1)) ⊦ r = null, dups(x), H[r].nxt ∈ x, ∃ x. path(r ' + x, H) ∧ (r ' + x).last = (H[r].nxt ' + x0).last ∧ ¬ r ∈ x ∧ ¬ dups(x), r ≠ H[r].nxt ∧ ¬ r ∈ x
Used simplifier rules: path-cons: ⊦ path(r ' + r0 ' + x, H) ↔ ¬ ¬(r ∈ H ∧ r ≠ null ∧ H[r].nxt = r0 ∧ path(r0 ' + x, H));%rec: ⊦ dups(r ' + x0) ↔ ¬ ¬(r ∈ x0 ∨ dups(x0)); from specification list-dup[reflist]%in-rec: ⊦ r ∈ r0 ' + x0 ↔ ¬ ¬(r = r0 ∨ r ∈ x0); from specification list[reflist]%l-05: ⊦ (r ' + r0 ' + x0).last = (r0 ' + x0).last; from specification list-last[reflist]%a: ⊦ (x0 + x1) + x2 = x0 + x1 + x2; from specification list[reflist]