query: $U \cup W$ not a vector subspace.
positive_passages.docid: 11301
positive_passages.text: Union of two vector subspaces not a subspace?
negative_passages.docid: 157742
negative_passages.text: Prove that $U(n)$ is a manifold
negative_passages.docid: 132386
negative_passages.text: Show that $(\mathbb{Q}^*,\cdot)$ and $(\mathbb{R}^*,\cdot)$ aren't cyclic
negative_passages.docid: 88474
negative_passages.text: $\mathbb{A}^{2}$ not isomorphic to affine space minus the origin
negative_passages.docid: 81229
negative_passages.text: Show that $(C([a,b]),\|{\cdot}\|_2)$ is not a complete normed vector space
negative_passages.docid: 18484
negative_passages.text: Show that $k[x,y,z]/(xz-y^2)$ is not a UFD.
negative_passages.docid: 55026
negative_passages.text: $\mathbb{Q}[X,Y]/(Y^2-X^3)$ is not a UFD
negative_passages.docid: 67191
negative_passages.text: When is the union of a family of subspaces of a vector space also a subspace?
negative_passages.docid: 84707
negative_passages.text: How to prove a cross is not locally homeomorphic to an euclidean space?
negative_passages.docid: 14713
negative_passages.text: $X=(-\infty,0]\cup\left\{{1\over n}:n\in\mathbb N\right\}$ with subspace topology Then
negative_passages.docid: 103460
negative_passages.text: Normal but not hermitian nor unitary
negative_passages.docid: 134065
negative_passages.text: A question about an $n$-dimensional subspace of $\mathbb{F}^{S}$.
negative_passages.docid: 41520
negative_passages.text: Prove that $L(V,W)$ forms a vector space
negative_passages.docid: 117185
negative_passages.text: The union of a strictly increasing sequence of $\sigma$-algebras is not a $\sigma$-algebra
negative_passages.docid: 70576
negative_passages.text: Elementary proof that $\mathbb{R}^n$ is not homeomorphic to $\mathbb{R}^m$
negative_passages.docid: 2813
negative_passages.text: What is (meant by) a non-compact $U(1)$ Lie group?
negative_passages.docid: 118903
negative_passages.text: The sup norm on $C[0,1]$ is not equivalent to another one, induced by some inner product