English
There is a natural ring homomorphism from α to its completion, given by the embedding.
Русский
Существует естественное кольцовомоморфное отображение from α в его дополнение, задаваемое вложением.
LaTeX
$$$\\mathrm{coeRingHom}: \\alpha \\to\\mathrm{Completion}(\\alpha)\\; \\text{is a ring homomorphism with } \\mathrm{toFun} = (↑)$$$
Lean4
/-- The map from a uniform ring to its completion, as a ring homomorphism. -/
def coeRingHom : α →+* Completion α where
toFun := (↑)
map_one' := coe_one α
map_zero' := coe_zero
map_add' := coe_add
map_mul' := coe_mul