Is it possible to construct a DFA that accepts the language of the empty set?
111349
Finite automaton that recognizes the empty language $\emptyset$
158728
Using induction for an easy proof for formal languages
101993
The cardinality of a language over a set of variables $V$ with $\#V= κ$
71653
Why is the Cartesian product of a set $A$ and empty set an empty set?
150605
Existence of a regular uncountable $\aleph_{\alpha}$ without $\mathsf{AC}$
84751
How can it be possible to localize a ring at a set with zero divisors?
124325
Element of, subset of and empty sets
65549
What is the cartesian product of an empty set of sets?
148028
Are there statements that are undecidable but not provably undecidable
10519
Describe in English a Turing machine that semidecides the following language - Is this solution correct?
16056
Is empty set element of every set if it is subset of every set?
14849
Decidability of a predicate.
151994
Why do first order languages have at most countably many symbols?
5374
How to check if a macro value is empty or will not create text with plain TeX conditionals?
45508
Is the empty set a group?
146891
Why is $\{\emptyset\} \not = \emptyset$?
88823
How can the empty set be open in the definition of the cofinite topology?