Sets identities on topological space
135751
Show that $Int(A)=X\setminus\overline{X\setminus A}$.
120345
Topology induced by seminorms and initial topology
28391
Prove the compactness of a set B
125174
Combinatorial intuition of identity
137438
Restrict a metric, gives same topology as subspace topology from larger space $X$
89264
Connectedness in the Quotient Space
80860
How to call a space in which every G$_\kappa$-set is open
128941
How to compute the topological space of fibered product of schemes?
62911
Let $(X,\tau)$ be a connected topological space, $Y\subset X$ connected and $U\subset X\setminus Y$ clopen. Prove that $ Y \cup U$ is connected
40071
What is the cardinality of the set of all topologies on $\mathbb{R}$?
66548
proving topological equivalence
77563
Homeomorphism between spaces equipped with cofinite topologies
85870
Show this set is a base for some topology on $\mathbb{Z}$
130156
Image of the union and intersection of sets.
41611
Open and closed set in n by n matrices space.
81843
Sequences of sets property
114061
Construct such $d$ that $(\mathbb{R} \setminus \mathbb{Z}, d)$ is complete metric space