Set theory; sets and subsets; Is an empty set contained within a set that contains real numbers?
74860
Why is the empty set a subset of every set?
32441
How to prove or disprove statements about sets
110677
How is an empty set truly "empty"?
50506
What concept does an open set axiomatise?
112910
Is the set of real numbers really uncountably infinite?
40662
What is the definition of a set?
153969
The "elements" of a real number
117561
A set is infinite iff there is a one-to-one correspondent with one of its proper subsets?
130771
Sets and the principle of inclusion and exclusion
58285
Is it true that if $X$ is connected, then for every nonempty proper subset $A$ of $X$, we have $\mathbf{Bd} \ne \emptyset$
44974
Infinite set and countable subsets
114608
Proof concerning regular space: there exist a closed set contained in any open set containing $x$
36721
Is "The empty set is a subset of any set" a convention?
60775
Why are integers subset of reals?
156946
The set of real numbers is a subset of the set of complex numbers?
73927
Is $\mathbb{R}$ a subset of $\mathbb{R}^2$?
13282
In the category $\mathbf{Set}$ is "the product of an empty set of sets a one-element set"?