Definition of a SET!
40662
What is the definition of a set?
26008
Why there is a unique empty set?
18364
When does the set enter set theory?
23334
Singular or plural "set"?
50258
How can a set contain itself?
39020
Why is empty set an open set?
36612
Strange set notation (a set as a power of 2)?
133522
How to change a set element?
86263
How do we show there are the same number of elements in each of the sets?
22482
How can an ordered pair be expressed as a set?
112290
Weird behavior of & function in Set
130771
Sets and the principle of inclusion and exclusion
73130
A simple question about open set
141299
Alternative set theories
125502
Empty set literal?
102543
Real definition of "countable set"
130418
Is ${\{\emptyset,\{\emptyset\},\{\{\emptyset\}\},\{\{\{\emptyset\}\}\},...\}} $ a set?