English
There is a normed additive commutative group structure on e.finiteSubspace given by x ↦ e(x) as its norm and the inherited metric.
Русский
На e.finiteSubspace задаётся нормированная абелева группа через x ↦ e(x) как норму и унаследованную метрику.
LaTeX
$$instance normedAddCommGroup : NormedAddCommGroup e.finiteSubspace := { norm := fun x => (e x).toReal, dist_eq := fun _ _ => rfl }$$
Lean4
/-- Normed group instance on `e.finiteSubspace`. -/
instance normedAddCommGroup : NormedAddCommGroup e.finiteSubspace :=
{ e.metricSpace with
norm := fun x => (e x).toReal
dist_eq := fun _ _ => rfl }