Is the word "empty" in set theory different from the word "empty" in ordinary language?
110677
How is an empty set truly "empty"?
136755
Direct proof of empty set being subset of every set
124325
Element of, subset of and empty sets
145574
Empty function, what is it?
45508
Is the empty set a group?
56637
In naive set theory ∅ = {∅} = {{∅}}?
1307
Infimum and supremum of the empty set
13282
In the category $\mathbf{Set}$ is "the product of an empty set of sets a one-element set"?
7443
Why is empty product defined to be $1$?
44160
Set theory: difference between belong/contained and includes/subset?
21374
What is exactly the difference between a definition and an axiom?
36721
Is "The empty set is a subset of any set" a convention?
23586
What is the difference between String.Empty and "" (empty string)?
55995
Why is the supremum of the empty set $-\infty$ and the infimum $\infty$?
125317
Is this statement "Every element in the empty set is greater than itself." true or its negation is true?
153551
Is the null set a subset of every set?
151825
Is there any difference between "foo is None" and "foo == None"?