| x0 ≠ [], H[x0.last].nxt = H[r2].nxt, (x0.last ' + x1).last = x0.last, x1 + r2 ' = H[r2].nxt ' + r0 ' + y, path(x0.last ' + x1, H), x0.last ∈ H, path(x0.last ' + x1 + r2 ', H), H[r2].nxt ∈ H, r2 ∈ H, path(r2 ' + x0, H), r2 = H[r2].nxt ∨ r2 = r0 ∨ r2 ∈ y, H[r2].nxt ∈ x1 ∨ H[r2].nxt = r2 ⊦ x0.last = null, x0.last = r2, H[r2].nxt = null, dups(x1), r2 ∈ x0, dups(x0), x0.last ∈ x1, r2 ∈ x1 |
H[x0.last].nxt = H[r2].nxt, (x0.last ' + x1).last = x0.last, x1 + r2 ' = H[r2].nxt ' + r0 ' + y, path(x0.last ' + x1, H), x0.last ∈ H, path(x0.last ' + x1 + r2 ', H), H[r2].nxt ∈ H, r2 ∈ H, path(r2 ' + x0, H), r2 = H[r2].nxt ∨ r2 = r0 ∨ r2 ∈ y, H[r2].nxt ∈ x1 ∨ H[r2].nxt = r2 ⊦ x0.last = null, x0.last = r2, H[r2].nxt = null, x0 = [], dups(x1), r2 ∈ x0, dups(x0), x0.last ∈ x1, r2 ∈ x1