| ∀ H, r. path(x0, H) → path(x0, H -- r) ∨ r ∈ x0, path(r0 + x0, H) ⊦ path(r0 + x0, H -- r), r ∈ r0 + x0 |
path(r0 ' + x0, H), ∀ H, r. path(x0, H) → path(x0, H -- r) ∨ r ∈ x0 ⊦ r = r0, path(r0 ' + x0, H -- r), r ∈ x0
Used simplifier rules: a: ⊦ (x0 + x1) + x2 = x0 + x1 + x2; from specification list[reflist]%in-06: ⊦ ¬ r ∈ r0 ' + x0 ↔ r ≠ r0 ∧ ¬ r ∈ x0; from specification list[reflist]%c: ⊦ r + x0 = r ' + x0; from specification list[reflist]