∀ {R : Type u_2} {E : Type u_3} {F : Type u_4} [inst : Semiring R] [inst_1 : PartialOrder R] [inst_2 : IsOrderedRing R]
  [inst_3 : AddCommMonoid E] [inst_4 : TopologicalSpace E] [inst_5 : Module R E] [inst_6 : AddCommMonoid F]
  [inst_7 : TopologicalSpace F] [inst_8 : Module R F] {x : E} {C : ProperCone R F} {f : E →L[R] F},
  x ∈ ProperCone.comap f C ↔ f x ∈ C