Is any subset of a $A$ of a separable norm linear space $X$ is separable?
139874
If $X^\ast $ is separable $\Longrightarrow$ $S_{X^\ast}$ is also separable
106487
Let $S$ and $W$ be subsets of a vector space $V$. Show that if $S$ is a subset of $W$, then $\mathrm{span}(S)$ is a subspace of $\mathrm{span}(W)$
49438
Prove that $X^\ast$ separable implies $X$ separable
66550
Cardinality of separable metric spaces
146143
Question about proof that finite-dimensional subspaces of normed vector spaces are direct summands
93771
Prove that for any set $A$ there is some $x \notin A$
28685
If every linear operator on $X$ is bounded then is $\dim X<\infty$?
67191
When is the union of a family of subspaces of a vector space also a subspace?
81229
Show that $(C([a,b]),\|{\cdot}\|_2)$ is not a complete normed vector space
155063
Is Cl(f(A)) a subset of f(Cl(A))?
155621
Finiteness of the dimension of a normed space and compactness
123665
A question in Subspaces in linear algebra
79779
How big can a separable Hausdorff space be?
53132
A convex subset of a set has 'smaller' boundary than the set?
132487
Proving that if $V$ is an inner product space and $U_1, U_2$ are subsets, then $U_1 \subset U_2$ if and only if $U^{\perp}_2 \subset U^{\perp}_1$
86749
Prove that any set of vectors $S \subset \mathbb{R}^n$ containing the zero vector cannot be linearly independent
154913
Are all the norms of $L^p$ space equivalent?