∀ {E : Type u_2} [inst : NormedAddCommGroup E] [inst_1 : InnerProductSpace ℝ E] [inst_2 : CompleteSpace E] (x : E),
  ProperCone.innerDual {x} = ProperCone.comap ((innerSL ℝ) x) (ProperCone.positive ℝ ℝ)