finite dimensional proper subspaces of a normed space are nowhere dense
- Let be a normed space. If is a finite dimensional proper subspace
, then is nowhere dense.
Proof :
It is known that for any topological vector space (in particular, normed spaces) every proper subspace has empty interior (http://planetmath.org/ProperSubspacesOfATopologicalVectorSpaceHaveEmptyInterior).
From the entry (http://planetmath.org/EveryFiniteDimensionalSubspaceOfANormedSpaceIsClosed) we also know that finite dimensional subspaces of are closed.
Then, , which shows that is nowhere dense.