| r2 ∈ x, path(r ' + x, H[r2, ce]), r ∈ H, x.last ∈ H ⊦ r2 ∈ H, r ∈ x, dups(x), reachable(r, x.last, H), ∃ r0. reachable(r, r0, H) ∧ H[r0].nxt = r2 ∧ H[r0].nxt ≠ null ∧ reachable(ce.nxt, x.last, H) |
⊦ r ∈ x0 ↔ (∃ x1, x2. x0 = x1 + (r + x2))
∃ x1, x2. x = x1 + (r2 + x2), path(r ' + x, H[r2, ce]), r ∈ H, x.last ∈ H ⊦ r2 ∈ H, r ∈ x, dups(x), reachable(r, x.last, H), ∃ r0. reachable(r, r0, H) ∧ H[r0].nxt = r2 ∧ H[r0].nxt ≠ null ∧ reachable(ce.nxt, x.last, H)
Used terms: x, r2