What do Logicians mean by a set?
18364
When does the set enter set theory?
50506
What concept does an open set axiomatise?
858
Is $\{\emptyset\}$ a subset of $\{\{\emptyset\}\}$?
54497
Set Notation - Inclusion and Proper Inclusion
9330
Meaning behind Filter in Set Theory
74860
Why is the empty set a subset of every set?
102543
Real definition of "countable set"
43814
What does it mean when a set is said to be a "finitely generated vector space"?
137460
How should I think of an open vs. closed set?
140742
What does the term "mathematical logic" mean?
75007
How can I prove this relation between the elementary set theory and the elementary logic?
14711
set theoretic function, products of sets (product versus Cartesian product)
77286
Proving set theory question
71653
Why is the Cartesian product of a set $A$ and empty set an empty set?
22804
Interpretation of limsup-liminf of sets
21374
What is exactly the difference between a definition and an axiom?
52451
Ordered Triples and Set Theory