| # x2 = n + 1, # x1 = n + 1, (H[r].nxt ' + x1).last = x2.last, path(H[r].nxt ' + x2, H), path(H[r].nxt ' + x1, H), reachable-1(H, H[r].nxt, r0), reachable-n(H, n, r0, x2.last), r ∈ H ⊦ r = null, x2 = [], ∃ r1. reachable-1(H, H[r].nxt, r1) ∧ reachable-n(H, n, r1, x2.last) |
Used terms: r0