What is the difference between "a" and "{a}" in set theory?
68244
Is ∅ equivalent to {∅}?
21374
What is exactly the difference between a definition and an axiom?
92390
The meaning of notation $\subset\subset$ in complex analysis
9330
Meaning behind Filter in Set Theory
93501
Order of precedence of set operators
62208
If $A$ is a non-empty set, then $A \notin A$
98271
Why does $(x \to a) ≠ (x = a)$ , But $f(x \to a) = f(x = a)$
113640
Why is there this strange contradiction between the language of logic and that of set theory?
47562
Confusion in symbol of subset.
146891
Why is $\{\emptyset\} \not = \emptyset$?
136835
ZF Set Theory - If $|A|^{|B|} = |B|$, then $|A| = 1 = |B|.$
40232
What do we mean when we say "Let $x$ be an element of the set $\mathbb{R}$"?
14512
Why cannot a set be its own element?
151215
Paradox of General Comprehension in Set Theory, other than Russell's Paradox
3148
True or false: {{∅}} ⊂ {∅,{∅}}
19138
If every object in math can be reduced to sets, how are tuples explained via sets?
75416
what is the difference between >&2 and &>2