| (r0 ' + x0).last = (r2 ' + x).last, (r ' + x1).last = (r2 ' + x).last, path(r0 ' + x0, H), r0 ∈ H, H[r0].nxt ∈ H, path(r ' + x1 + r2 ' + (x + H[r0].nxt ') + r0 ', H), path(r ' + x1 + r2 ' + x + H[r0].nxt ', H), path(r ' + x1, H), (r2 ' + x).last ∈ H ⊦ r2 = r0, r = r2, r0 = r, H[r0].nxt = null, r0 = H[r0].nxt, r2 = H[r0].nxt, r = H[r0].nxt, r ∈ x1, dups(x0), r0 ∈ x0, r0 ∈ x, H[r0].nxt ∈ x, H[r0].nxt ∈ x1, dups(x1 + x), r0 ∈ x1, r2 ∈ x, r2 ∈ x1, r ∈ x, dups(x1), dups(x) |
⊦ x0 ≠ [] → (x1 + x0).last = x0.last
¬ x ≠ [], (r0 ' + x0).last = (r2 ' + x).last, (r ' + x1).last = (r2 ' + x).last, path(r0 ' + x0, H), r0 ∈ H, H[r0].nxt ∈ H, path(r ' + x1 + r2 ' + (x + H[r0].nxt ') + r0 ', H), path(r ' + x1 + r2 ' + x + H[r0].nxt ', H), path(r ' + x1, H), (r2 ' + x).last ∈ H ⊦ r2 = r0, r = r2, r0 = r, H[r0].nxt = null, r0 = H[r0].nxt, r2 = H[r0].nxt, r = H[r0].nxt, r ∈ x1, dups(x0), r0 ∈ x0, r0 ∈ x, H[r0].nxt ∈ x, H[r0].nxt ∈ x1, dups(x1 + x), r0 ∈ x1, r2 ∈ x, r2 ∈ x1, r ∈ x, dups(x1), dups(x)
x ≠ [], (r0 ' + x0).last = x.last, (r ' + x1).last = x.last, path(r0 ' + x0, H), r0 ∈ H, H[r0].nxt ∈ H, path(r ' + x1 + r2 ' + (x + H[r0].nxt ') + r0 ', H), path(r ' + x1 + r2 ' + x + H[r0].nxt ', H), path(r ' + x1, H), x.last ∈ H ⊦ r2 = r0, r = r2, r0 = r, H[r0].nxt = null, r0 = H[r0].nxt, r2 = H[r0].nxt, r = H[r0].nxt, r ∈ x1, dups(x0), r0 ∈ x0, r0 ∈ x, H[r0].nxt ∈ x, H[r0].nxt ∈ x1, dups(x1 + x), r0 ∈ x1, r2 ∈ x, r2 ∈ x1, r ∈ x, dups(x1), dups(x)
Used terms: x, r2 '