Is this condition for the union of a collection of subspaces to be a subspace?
67191
When is the union of a family of subspaces of a vector space also a subspace?
80156
Formatting the union of sets
153747
Sub-dimensional linear subspaces of $\mathbb{R}^{n}$ have measure zero.
78833
Can a basis for a vector space $V$ can be restricted to a basis for any subspace $W$?
106756
Union and Intersection of Sets $A_{i}$ and $B_{j}$
92774
Prove that a linear subspace of $C([0,1])$ is closed
11301
Union of two vector subspaces not a subspace?
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 $\mathrm{span}(W)$
94405
Let $W$ be the set of all linear combinations of $v_1,...,v_n$. Then $W$ is a subspace of $V$.
4717
The union of linear subspaces is not necessarily a subspace
14429
dimension of a subspace spanned by two subspaces
70413
A vector space over $R$ is not a countable union of proper subspaces
48579
How to find the orthogonal complement of a subspace?
28819
A union of two subspaces not equal to the vector space.
123408
Why a subspace of a vector space is useful
23740
Confused about the definition of subspace
147793
A variation on the induced topology (subspace topology)