| ce.nxt = H[H[r0].nxt].nxt, path(r ' + x1 + H[r0].nxt ', H[r0, ce]), reachable(r, r0, H), H[r0].nxt ∈ H[r0, ce], r0 ∈ H, H[r0].nxt ∈ H, r0 ∈ x1, ∀ r1. ¬ reachable(H[r1].nxt, r1, H) ⊦ H[r0].nxt = null, r = H[r0].nxt, dups(x1), H[r0].nxt ∈ x1, r ∈ x1 |
⊦ r ∈ x0 ↔ (∃ x1, x2. x0 = x1 + r ' + x2 ∧ ¬ r ∈ x2)
ce.nxt = H[H[r0].nxt].nxt, path(r ' + x1 + H[r0].nxt ', H[r0, ce]), reachable(r, r0, H), H[r0].nxt ∈ H, r0 ∈ H, H[r0].nxt ∈ H[r0, ce], ∀ r1. ¬ reachable(H[r1].nxt, r1, H), ∃ x, x2. x1 = x + r0 ' + x2 ∧ ¬ r0 ∈ x2 ⊦ H[r0].nxt = null, r = H[r0].nxt, dups(x1), r ∈ x1, H[r0].nxt ∈ x1
Used terms: x1, r0