∀ {K : Type u_1} [inst : Field K] [inst_1 : NumberField K] (x y : NumberField.mixedEmbedding.realSpace K),
  ↑NumberField.mixedEmbedding.fundamentalCone.expMap (x + y) =
    ↑NumberField.mixedEmbedding.fundamentalCone.expMap x * ↑NumberField.mixedEmbedding.fundamentalCone.expMap y