∀ {𝕜 : Type u_1} {β : Type u_5} [inst : Field 𝕜] [inst_1 : LinearOrder 𝕜] [IsStrictOrderedRing 𝕜]
  [inst_3 : AddCommMonoid β] [inst_4 : LinearOrder β] [IsOrderedCancelAddMonoid β] [inst_6 : Module 𝕜 β]
  [PosSMulStrictMono 𝕜 β] {x y z : 𝕜} {s : Set 𝕜} {f : 𝕜 → β},
  ConcaveOn 𝕜 s f → x ∈ s → z ∈ s → x < y → y ≤ z → f y ≤ f x → f z ≤ f y