Riesz lemma
= Riesz lemma
{c}
{wiki=Riesz's_lemma}
If $Y$ is a proper closed subspace of a normed space $X$ and $0<\alpha<1$, there is a unit vector $x\in X$ whose distance from $Y$ exceeds $\alpha$.
= Riesz lemma
{c}
{wiki=Riesz's_lemma}
If $Y$ is a proper closed subspace of a normed space $X$ and $0<\alpha<1$, there is a unit vector $x\in X$ whose distance from $Y$ exceeds $\alpha$.