Is $\mathbb{R}$ a subset of $\mathbb{R} \times \mathbb{R}$?
73927
Is $\mathbb{R}$ a subset of $\mathbb{R}^2$?
81196
Is true that $H^{s,p}(\mathbb{R}^n)\subset C^k(\mathbb{R}^n)$ when $s-k>n/p$?.
84189
Is $\mathbb{C}$ equal to $\mathbb{R}^2$?
130297
$A$ be a subset of $[0,1]$ with non-empty interior ; then is it true that $\mathbb Q+A=\mathbb R$?
63267
Under what conditions on the sets $A$ and $B$ will it be true that $A\times B= B\times A$
109710
Bijection between $\mathbb N \times \mathbb N$ and $\mathbb N$
151295
Proving $|S \times \mathbb{N}|=|S|$ when $S$ is an infinite set
75829
Dimension of open subsets of $R^n$
132311
T$\mathbb{S}^{n} \times \mathbb{R}$ is diffeomorphic to $\mathbb{S}^{n}\times \mathbb{R}^{n+1}$
40071
What is the cardinality of the set of all topologies on $\mathbb{R}$?
66239
Verifying that a certain collection of intervals of $\mathbb R$ forms a topology
92740
prove that $\mathbb{Q}^n$is dense subset of $\mathbb{R^n}$
4538
Is the mapping $ d : X\times X \mapsto \mathbb {R} $ continuous?
1591
What does $\mathbb{R} \setminus S$ mean?
90239
$\mathbb{Z} \times \mathbb{Z}$ is cyclic.
78108
Do these define metrics on $\mathbb{R}$?
45991
Why $f\colon \mathbb{Z}_n^\times \to \mathbb{Z}_m^\times$ is surjective?