| ¬ y ≠ [], x1 + r2 ' + x2 = x + H[(r0 ' + y).last].nxt ' + (r0 ' + y).butlast, ((r0 ' + y).last ' + x0).last = (r ' + x).last, (r ' + x1).last = (r ' + x).last, (r ' + x).last ∈ H, path(r ' + x1, H), path(r ' + x + H[(r0 ' + y).last].nxt ', H), path(r ' + x1 + r2 ' + x2 + (r0 ' + y).last ', H), H[(r0 ' + y).last].nxt ∈ H, (r0 ' + y).last ∈ H, path((r0 ' + y).last ' + x0, H), (r0 ' + y).last = H[(r0 ' + y).last].nxt ∨ (r0 ' + y).last = r0 ∨ (r0 ' + y).last ∈ y ⊦ H[(r0 ' + y).last].nxt = null, (r0 ' + y).last = r, r = r2, r2 = (r0 ' + y).last, (r0 ' + y).last ∈ x, (r0 ' + y).last ∈ x0, dups(x0), r ∈ x1, r ∈ x2, r2 ∈ x1, r2 ∈ x2, (r0 ' + y).last ∈ x1, (r0 ' + y).last ∈ x2, dups(x1 + x2), dups(x1), dups(x2) |
(r0 ' + x0).last = (r ' + x).last, x1 + r2 ' + x2 = x + H[r0].nxt ', (r ' + x1).last = (r ' + x).last, path(r0 ' + x0, H), r0 ∈ H, H[r0].nxt ∈ H, path(r ' + x1 + r2 ' + x2 + r0 ', H), path(r ' + x1 + r2 ' + x2, H), path(r ' + x1, H), (r ' + x).last ∈ H, H[r0].nxt ∈ x1 ∨ H[r0].nxt = r2 ∨ H[r0].nxt ∈ x2 ⊦ r2 = r0, r = r2, r0 = r, H[r0].nxt = null, r0 ∈ x2, r0 ∈ x1, r2 ∈ x2, r2 ∈ x1, r ∈ x2, r ∈ x1, dups(x0), r0 ∈ x0, r0 ∈ x, dups(x2), dups(x1), dups(x1 + x2)
Used simplifier rules: in-rec: ⊦ r ∈ r0 ' + x0 ↔ ¬ ¬(r = r0 ∨ r ∈ x0); from specification list[reflist]%in-append: ⊦ r ∈ x0 + x1 ↔ ¬ ¬(r ∈ x0 ∨ r ∈ x1); from specification list[reflist]%in-15: ⊦ x0 + r ' = x1 → r ∈ x1; (forward) from specification list[reflist]%b: ⊦ r '.butlast = []; from specification list-last[reflist]%l: ⊦ r '.last = r; from specification list-last[reflist]%a: ⊦ (x0 + x1) + x2 = x0 + x1 + x2; from specification list[reflist]%app: ⊦ x0 + [] = x0; from specification list[reflist]