Finding the closure of set
106944
Is the set defined by y=sin(1/x) open or closed?
84609
Unary intersection of the empty set
131841
Difference of closures and closure of difference
21820
How to prove that a set is invariant?
48535
Obtaining a powerset of a set in Java
148992
A finite set is closed
63717
Is the closure of a set equal to the closure of the closure of that set?
70327
the numer of partial function between two sets in combinatoric way
78117
Closed property of nonempty finite set
73130
A simple question about open set
10180
How to prove that this set is closed?
58004
showing a collection of sets contain all closed sets
13906
How to prove the set $S$ is closed under the binary operation $a*b=a+b+kab$?
81550
Linking two theorems: on algebraic closure and on minimal splitting field
120685
Topology induced from Kuratowski Closure properties
142886
Find set with maximal cardinality given constraints
143457
Is product of two closed sets closed?