∀ {V : Type u_1} {G : SimpleGraph V} {v : V} [inst : DecidableEq V] {c : G.Walk v v}
  (this_1 : List.count v c.support.tail = 1),
  (List.findIdxs (fun x => decide (x = v)) c.support.tail)[0] + 1 ≤ c.support.tail.length →
    (List.findIdxs (fun x => decide (x = v)) c.support.tail)[0] < c.support.tail.length