∀ {M : Type u_1} [inst : AddSemigroup M] {motive : (a : Stream' M) → (a_1 : M) → Hindman.FS a a_1 → Prop}
  (a : Stream' M) (m : M) (h : Hindman.FS a.tail m), Hindman.FS.below h → motive a.tail m h → Hindman.FS.below ⋯