| path(r ' + x, H), x.last ∈ H ⊦ x = [], r2 ∈ H, path(r ' + x, H[r2, ce]) |
∀ r, H, r2, ce. path(r ' + x0, H) ∧ x0.last ∈ H → x0 = [] ∨ r2 ∈ H ∨ path(r ' + x0, H[r2, ce]), path(r ' + (r0 + x0), H), (r0 + x0).last ∈ H ⊦ r0 + x0 = [], r2 ∈ H, path(r ' + (r0 + x0), H[r2, ce])
Used simplifier rules: reflist freely generated by [], +;;