| ce.nxt = null, path(r ' + x, H[r2, ce]), (r ' + x).last ∈ H ⊦ path(r ' + x, H), r2 ∈ H |
ce.nxt = null, path(r ' + (r0 + x0), H[r2, ce]), (r ' + (r0 + x0)).last ∈ H, ∀ ce, r, H, r2. ce.nxt = null ∧ path(r ' + x0, H[r2, ce]) ∧ (r ' + x0).last ∈ H → path(r ' + x0, H) ∨ r2 ∈ H ⊦ path(r ' + (r0 + x0), H), r2 ∈ H
Used simplifier rules: path-one: ⊦ path(r ', H) ↔ r ∈ H ∧ r ≠ null;%reflist freely generated by [], +;;% ⊦ x0 + [] = x0; (s)%a: ⊦ (x0 + x1) + x2 = x0 + x1 + x2; from specification list[reflist]% ⊦ r '.last = r; (s)