Mathematics Stack Exchange
Mathematics Stack Exchange

Questions tagged [notation]

Questions on the meaning, history, and usage of mathematical symbols and notation. Please remember to mention where (book, paper, webpage, etc.) you encountered any mathematical notation you are asking about.

Before asking a question on the site, please check if you can find your answer in Earliest Uses of Various Mathematical Symbols or the book A History of Mathematical Notations.

Alternatively, a textbook or paper usually takes the time to explain the notation they're using; please remember to mention where you've seen the notation you are asking about.

12848 questions
1
vote
0 answers

Geometric Notation

What is does the curve on top of EB in the picture mean?
BarryAllen
  • 11
1
vote
0 answers

What is the Math Notation for composing $n$ functions?

Suppose I have $n$ functions namely $f_1,...,f_n$. If I want to sum them then I could use Sigma $\Sigma$, if I want to multiply them, I could use capital Pi $\Pi$. But what if I want to compose all of them? Is there a known notation convention for…
AspiringMat
  • 2,483
  • 1
  • 17
  • 32
1
vote
2 answers

If E' is the set of all limit points of a set E what does (E')' represent?

The answer to this question is sure to make me feel embarrassed, but here we go: I am wondering about notation if $E'$ is the set of limit points of a set E, then what does $\left(E'\right)'$ mean? The reason I wonder is since the book uses $E^c$…
ALEXANDER
  • 2,099
1
vote
0 answers

How do you call the "type signature" vs the "function implementation"

I often throw around signatures like: $$f: X \times X \to X$$ and $$f: (x_1, x_2) \mapsto x_1 \cdot x_2$$ But how do you call these kinds of signatures? EDIT: Some clarification: The first version maps sets and uses $\to$ The second version maps…
hgiesel
  • 1,257
1
vote
0 answers

About the Name of Theorem or Lemma

I just have a question which may not be of much importance, but just curious. We have Zorn's lemma, Schur's lemma, Gauss's theorem, Cayley's theorem, Poincare lemma, Gauss lemma, Hilbert basis theorem, and Noether theorem. I note that when a name is…
User
  • 1,687
1
vote
1 answer

Notation: Elementwise cropping for vectors

I am looking for a notation for following function: A vector $\vec{a}$ is normalized using L2-norm. But if the value of one element is bigger then a hysteresis an other value $h$ is used. For example after normalization $\vec{a} = [1, 2, 3, 4]$ and…
lightninglord
  • 11
  • 1
1
vote
2 answers

Properly writing that a set of variables take values from a certain set?

I have a pretty dumb question. I know that if I have a pair $(a,b)$ that can take values in $\mathbb{R}$, I should write $(a,b) \in \mathbb{R}^2$. But what about if I have a set? I want $\{a,b,c\}$ to all take values in $[1,3] = \{1,2,3\}$. Do I…
excalibur1491
  • 137
1
vote
1 answer

Notation for Domain with Discontinuities

At my school we are going over rational functions and discontinuities, and we often are asked to find the domain/range of a function. Sometimes the range feels quite lengthy, however, which is why I'm asking this question. For example, look at the…
Krypto14
  • 141
  • 3
  • 10
1
vote
1 answer

Notation for the exclusive choice from the set

I have the following formula: $$ \Omega \subset \mathbb{R}^d, $$ where $d=2$ or $d=3$. But I find this style of notation quite cumbersome. Is there any way, how to note, that $d$ equals to 2 or 3 exclusively and in more elegant way?
Eenoku
  • 894
1
vote
1 answer

How to express the digit place of a decimal number?

I have a computer program which outputs decimal numbers with a one's place and one digit after the decimal point, for example 2.5 or 3.0. The program can only output a 0 or a 5 after the decimal, so if it computes 4.4 it will round this down to…
AbuMariam
  • 113
1
vote
2 answers

How would I express that a variable is a very small number?

I was wondering if there were a mathematical way to note that a variable in an expression is "very small". I feel like ambiguity might be the cause of there not being one, but I'm not sure. Example: $\Delta A = \frac12 (r + \Delta r)^2 \Delta \theta…
Dylan
  • 15
1
vote
0 answers

How to denote the intersection of two strings?

Question I would like to know what notation can be used to represent the intersection of two strings. First things first When I say string I refer to a sequence of characters in computer science ("EXAMPLE") for instance. When I say substring I mean…
Ilhan
  • 331
1
vote
1 answer

Postfix notation and the equals operator

Does the equals sign exist in postfix notation? For example: how would you display 1 + 2 = 3 in postfix notation? Is it 1 2 + 3?
Gordan W.
  • 11
  • 1
1
vote
0 answers

Notation for similar terms

Look at the expression example from the linear algebra ($A: V \to W$ is a linear mapping): $$\operatorname{im} A = \operatorname{range} A = A(V) = \{ A(x) \: | \: x \in V \}$$ Here is a feature: the first three terms $(\:\operatorname{im} A,…
Rodvi
  • 494
1
vote
1 answer

Notation for a periodic interval?

For instance, if I want to describe the position on a circle I can write that the angle $\theta$ can be found in the interval $[0, \tau)$, but how can I express that this interval is periodic, e.g. that $0$ and $\tau^-$ are "glued" together?
Frank Vel
  • 5,339
1 2 3
…
99 100