English
There is a canonical ring homomorphism from a number field K into the mixed space, obtained by pairing the real embeddings with the complex embeddings:
Русский
Существует каноническое кольцеобразное вложение из числа поля K в смешанное пространство, получаемое сочетанием вещественных и комплексных вложений.
LaTeX
$$$\text{mixedEmbedding}: K \to^+_* \mathrm{mixedSpace}(K) \quad\text{is given by}\quad x \mapsto\left( w \mapsto \text{embedding of } x \text{ at } w,\; w \mapsto \text{embedding of } x \text{ at } w\right).$$$
Lean4
/-- The mixed embedding of a number field `K` into the mixed space of `K`. -/
noncomputable def _root_.NumberField.mixedEmbedding : K →+* (mixedSpace K) :=
RingHom.prod (Pi.ringHom fun w => embedding_of_isReal w.prop) (Pi.ringHom fun w => w.val.embedding)