| ce.nxt = H[H[r0].nxt].nxt, r0 ∈ x2, path(r ' + x2 + H[r0].nxt ', H[r0, ce]), path(r ' + x1 + r0 ', H), H[r0].nxt ∈ H, r0 ∈ H, H[r0].nxt ∈ H[r0, ce] ⊦ H[r0].nxt = ce.nxt, H[r0].nxt = null, r = H[r0].nxt, r ∈ x1, r0 ∈ x1, dups(x1), r ∈ x2, H[r0].nxt ∈ x2, dups(x2), ∃ x0. path(H[r0].nxt ' + x0 + H[r0].nxt ', H) ∧ ¬ r0 ∈ x0, ∃ x. path(r ' + x + H[r0].nxt ', H) ∧ ¬ r0 ∈ x |
⊦ r ∈ x0 ↔ (∃ x1, x2. x0 = x1 + r ' + x2 ∧ ¬ r ∈ x1)
ce.nxt = H[H[r0].nxt].nxt, ∃ x1, x. x2 = x1 + r0 ' + x ∧ ¬ r0 ∈ x1, path(r ' + x2 + H[r0].nxt ', H[r0, ce]), path(r ' + x1 + r0 ', H), H[r0].nxt ∈ H, r0 ∈ H, H[r0].nxt ∈ H[r0, ce] ⊦ H[r0].nxt = ce.nxt, H[r0].nxt = null, r = H[r0].nxt, r ∈ x1, r0 ∈ x1, dups(x1), r ∈ x2, H[r0].nxt ∈ x2, dups(x2), ∃ x0. path(H[r0].nxt ' + x0 + H[r0].nxt ', H) ∧ ¬ r0 ∈ x0, ∃ x. path(r ' + x + H[r0].nxt ', H) ∧ ¬ r0 ∈ x
Used terms: x2, r0