| reachable-n(H, m0, H[r] .nxt, r0), r ∈ H, H[r] .nxt ∈ H, reachable-n(H, m, H[r] .nxt, r) ⊦ H[r] .nxt = null, r = null, reachable-n(H, m + 1, r0, r0), ∃ r1. reachable-n(H, m, H[r] .nxt, r1) ∧ reachable-1(H, r1, H[r] .nxt) |
[[CONCRETESIMPRULES : ([CSIMPSEQ : ⊦ reachable-1(H, r, r0) ↔ r ≠ null ∧ r0 ≠ null ∧ r ∈ H ∧ r0 ∈ H ∧ H[r] .nxt = r0])], [EXTRATERMS : (r)]]