How to see $A=\{ (x,y) \in \mathbb{R}^2 : x \in \mathbb{N}, y \in \mathbb{R} \}$ has empty interior?
68977
Interior of cartesian product is cartesian product of interiors
62208
If $A$ is a non-empty set, then $A \notin A$
858
Is $\{\emptyset\}$ a subset of $\{\{\emptyset\}\}$?
47680
Prove that the union of the interior of a set and the boundary of the set is the closure of the set
44685
Inner product on $C(\mathbb R)$
35631
$H_0(X,A) = 0 \iff A \cap X_i \neq \emptyset \forall $ path-components $X_i$
155579
Show that $End_A(A)$ = {$r_a$ | $a ∈ A$}
21599
$(0,1)$ is an open subset of $\mathbb{R}$ but not of $\mathbb{R}^2$, when we think of $\mathbb{R}$ as the x-axis in $\mathbb{R}^2$. Prove this.
105014
Is the zero vector in $\mathbb{R}^n$ by itself a subspace of $\mathbb{R}^n$?
132716
how to typeset empty inner product
46622
Let $ Y = \{ (1,1),(0,0\} \subset \mathbb A_k^2$. Find the $ \mathbb I(Y)$.
81351
Polish space in which the interior of each compact set is empty
121198
$W^{1,1}(\mathbb{R}^n)$ is not compactly embedded in $L^1(\mathbb{R}^n)$?
91087
For which values $r, s \in \mathbb R$ is the set $\{u, v, w\}$ linearly independent?
43535
show that the interval of the form $[0,a)$ or $(a, 1]$ is open set in metric subspace $[0,1]$ but not open in $\mathbb R^1$
14215
Show that the union $\bigcup A_n$ has empty interior in $X$
1307
Infimum and supremum of the empty set