| path(H[r].nxt ' + x0, H), r ∈ H, ∀ r, H. path(r ' + x0, H) → x0 = [] ∨ r = null ∨ (∃ n. reachable-n(H, n, r, x0.last)) ⊦ r = null, ∃ n. reachable-n(H, n, r, (H[r].nxt ' + x0).last) |
x0 = [], path(H[r].nxt ' + x0, H), r ∈ H, ∀ r, H. path(r ' + x0, H) → x0 = [] ∨ r = null ∨ (∃ n. reachable-n(H, n, r, x0.last)) ⊦ r = null, ∃ n. reachable-n(H, n, r, (H[r].nxt ' + x0).last)
path(H[r].nxt ' + x0, H), r ∈ H, ∀ r, H. path(r ' + x0, H) → x0 = [] ∨ r = null ∨ (∃ n. reachable-n(H, n, r, x0.last)) ⊦ x0 = [], r = null, ∃ n. reachable-n(H, n, r, (H[r].nxt ' + x0).last)
Used formulas: x0 = []