Wikipedia
en.wikipedia.org › wiki › Null_sign
Null sign - Wikipedia
8 hours ago - ... U+0444 ф CYRILLIC SMALL LETTER EF are a part of the Cyrillic script. The letter took the place of fita ( ... U+0473 ѳ CYRILLIC SMALL LETTER FITA), a letter of Early Cyrillic alphabet in modern usages. In mathematics, the null sign (∅) denotes the empty set...
Top answer 1 of 2
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According to Wikipedia André Weil (and maybe others) introduced the symbol 
for the empty set. They were inspired by the letter Ø in the Norwegian and Danish alphabet. So, I guess you could argue that the symbol should be pronounced as it is pronounced in these alphabets.
In my experience most mathematicians just call the symbol "empty set".
Note also, that the Wikipedia article says that the symbol is not to be confused with the Greek letter 
or 
.
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Although not mathematics, I thought I would add that in the APL programming language the empty vector is represented by the symbol ⍬, which is pronounced "zilde".
What is a null set example?
A null set would be: { }. This is simply a set that contains no elements. The brackets indicate a set and since there are no elements listed within, the set is empty.
study.com
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Null Set Definition, Properties & Examples - Lesson | Study.com
What is a null set called?
A null set is also called an empty set. These terms are used interchangeably to describe a set that contains no elements.
study.com
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Null Set Definition, Properties & Examples - Lesson | Study.com
How do you define a null set?
The null set is the set containing zero elements. So, any set containing no elements is defined to be the null set.
study.com
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Null Set Definition, Properties & Examples - Lesson | Study.com
Videos
04:28
What is the Null Set? (Empty Set, Void set, ∅, {}) Axiomatic ...
03:07
Why is the Empty Set a Subset of Every Set? | Set Theory, Subsets, ...
02:08
What is a Null Set | Is Null Set a Subset of Every Set? | Don't ...
02:08
The Empty Set or the Null Set , Intermediate Algebra , Lesson 27 ...
Empty Set - YouTube
04:35
What is the Power Set of the Empty Set? | Set Theory - YouTube
Physics Read
physicsread.com › home › how to write an empty(or null) set symbol(∅) in latex?
How to Write an Empty(or Null) Set Symbol(∅) in LaTeX?
September 24, 2025 - In LaTeX, the most commonly used command to represent the empty set is \emptyset. It is widely accepted and does not require any additional packages. \(p=\left \{ x:x^{2}=4,x\:is\:odd\right \} \) \( \therefore p=\emptyset \) ... In above code, the \: command is used to add extra space between words in the equation, improving readability. Alternatively, the \O command can be used for the same symbol.
Online Math Learning
onlinemathlearning.com › empty-set.html
Empty Set Or Null Set And Equal Sets (video lessons, examples and solutions)
It is represented by the symbol { } or Ø. Some examples of null sets are: The set of dogs with six legs. The set of squares with 5 sides. The set of cars with 200 doors. The set of integers which are both even and odd.
Third Space Learning
thirdspacelearning.com › home › gcse maths › set notation
Set Notation - GCSE Maths - Steps, Examples & Worksheet
August 20, 2023 - We also have the empty set (or null set), \phi , which contains no elements. For example, from the universal set \xi = \{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12\}, the set B = \{ numbers greater than 12\} = \phi , because there are no numbers ...
Reddit
reddit.com › r/mathematics › what letter is the empty set symbol ∅ to you?
r/mathematics on Reddit: What letter is the empty set symbol ∅ to you?
April 7, 2024 - So this does add an extra layer of complexity, because if hypothetically even if the empty set ∅ were a variant of phi or the Danish slashed O, it would have probably ended up as a separate codepoint in Unicode anyway. Hope this helps. More replies More replies ... I've never seen anyone use any variation of phi, ever. I think the confusion about the difference between the Danish "slashed-O" *letter* and the *symbol* representing the empty set comes from absolute ugly monstrosity that \emptyset is in default LaTeX.
Google Groups
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Re: How do I make a "null sign?"
Type capital O. Mark this character. Then, in the third group of icons (Embellishments) click slash (third icon). This will result in the symbol of empty set.
Study.com
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Null Set Definition, Properties & Examples - Lesson | Study.com
July 7, 2016 - Here is a list of common notations used for the null set: ... The first notation comes from the definition of set in set theory. A set is usually depicted as a list of elements between curled brackets. Therefore, the empty set can be shown as a set with no elements inside the brackets. The last two symbols are very similar.
CK-12 Foundation
flexbooks.ck12.org › cbook › ck-12-cbse-maths-class-11 › section › 1.4 › primary › lesson › empty-set
Empty Set - Definition, Symbol, Cardinality, Examples and ...
January 1, 2026 - We cannot provide a description for this page right now
Aphtech
uebmath.aphtech.org › lesson7.0
Lesson 7.0: Set Notation: Complements and Subsets
The symbol for a subset (contained in or equal to) ⊆, is the subset symbol with a horizontal line displayed beneath it. The symbol for contained in or equal to is three cells; dots four five six in the first cell, dots four five in the second cell, and dots one two six in the third cell. ... The empty or null set denoted by ∅, is also a subset of any given set.
Wikipedia
en.wikipedia.org › wiki › Empty_set
Empty set - Wikipedia
February 4, 2026 - U+2205 ∅ EMPTY SET. It can be coded in HTML as ∅ and as ∅ or as ∅. It can be coded in LaTeX as \varnothing. The symbol
Top answer 1 of 2
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Another suggestion is you can also type: Alt + 0216.
Best regards,
Dan
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Hi! I'm Dan! An Independent Advisor and also a Microsoft user for several years. I'll be more than happy to assist you today!
Method 1:
The ∅ symbol can be entered by going into "Symbols", choose "Mathematical Characters" and from the dropdown "Subset".
Method 2:
Type 2205 and then press "Alt + X".
I hope this information is helpful. Please keep me updated on the status of this issue. If you have any more questions, feel free to ask and I will be glad to assist you.
Standard Disclaimer: There are links to non-Microsoft websites. The pages appear to be providing accurate, safe information. Watch out for ads on the sites that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the sites before you decide to download and install it.
Best regards,
Dan
Cuemath
cuemath.com › algebra › empty-set
Empty Set - Definitions, Properties, Examples | Null Set
A set that does not contain any element is called an empty set or a null set. An empty set is denoted using the symbol '∅'. It is read as 'phi'. Example: Set X = {}. It is also called a void set or null set.
Quora
quora.com › What-is-the-name-of-the-symbol-Which-we-use-for-empty-set-in-mathematics
What is the name of the symbol ∅ ? Which we use for empty set in mathematics. - Quora
What is the name of the symbol ∅ ? Which we use for empty set in mathematics. ... PhD in Mathematics; Mathcircler. · Upvoted by · Robby Goetschalckx, Computer scientist for 11+ years and passionate about math since childhood. · Author has 8.8K answers and 178.4M answer views · 4y · It is called the Null Sign.
CK-12 Foundation
ck12.org › all subjects › cbse math › sets and its types › what symbol denotes an empty or null set?
What symbol denotes an empty or null set? - Examples, Symbol, & Definition | CK-12 Foundation
September 11, 2025 - In mathematics, an empty set, also known as a null set, is a set that contains no elements. It is denoted by the symbol @$\begin{align*}\emptyset\end{align*}@$ or by @$\begin{align*}\{\}\end{align*}@$. For example, the set of all integers that are both even and odd is an empty set, because ...
TechTarget
techtarget.com › whatis › definition › data-set
What is a null set in mathematics?
[ "row-frzi_7bar_4cbg", "00000000-0000-0000-AF08-C339B5581012", 0, 1698955938, null, 1698955938, null, "{ }", "172653", "375", "Nitrogen dioxide (NO2)", "Mean", "ppb", "UHF34", "203", "Bedford Stuyvesant – Crown Heights", "Annual Average 2011", "2010-12-01T00:00:00", "25.30", null ]
Piliapp
piliapp.com › symbols › null-sign
∅ Null Sign - PiliApp
It is unique in that it is a subset of every set, including itself. Windows: Hold down the Alt key and type 8709 on the numeric keypad, then release the Alt key. Mac: Press Option + 0. Linux: Press Ctrl + Shift + u, then type 2205 and press Enter. HTML: Use the named entity ∅ or the numeric ...
SplashLearn
splashlearn.com › home
Empty Set: Definition, Properties, Notation, Symbol, Examples
February 5, 2024 - More Worksheets · The empty set is denoted by $∅$ or $\left\{ \right\}$. As mentioned earlier, we can represent an empty set either with a special symbol ∅ or with the conventional curly brackets { } with no elements inside.
Quora
quora.com › What-is-the-name-of-the-symbol-used-for-expressing-empty-sets
What is the name of the symbol used for expressing empty sets? - Quora
Answer: It’s called the “empty set symbol.” I wish I could give you some cool name like “octothorpe”, but it was based on the letter Ø from Danish, where it is a Close-mid front rounded vowel and “the name of this letter is the same as the sound it represents” [1]. The first link has a short au...