∀ {β : Type u_1} (motive : ForInStep β → Sort u_2) (r : β) (h_1 : (r : β) → motive (ForInStep.done r))
  (h_2 : (r : β) → motive (ForInStep.yield r)),
  (match ForInStep.done r with
    | ForInStep.done r => h_1 r
    | ForInStep.yield r => h_2 r) =
    h_1 r