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
2
votes
1 answer

Notation for appending the same element to each set of a set of sets

If I had a set $A = \{\{1, 2\}, \{2, 3\}, \{1, 3\}\}$, how would I go about notating the set $B = \{\{1, 2, 4\}, \{2, 3, 4\}, \{1, 3, 4\}\}$ without explicitly writing out $B$? More generally, if I had a set of sets $A$, how would I denote the set…
VSCloud9
  • 92
2
votes
1 answer

How is a bigram defined mathematically?

I know what a bigram is, intuitively (in a string it's two contiguous symbols). However, I found this mathematical definition in a book and there is one part that keeps tripping me up, namely the $2-grams(w)$ function. Definition 3.2 (Bigrams).…
alpablo20
  • 123
  • 4
2
votes
2 answers

In which countries are the $_nC_k$ notation used instead of $\binom{n}{k}$

I have read this somewhere before but I cannot find the source any more. I have seen the binomial coefficient written as $_nC_k$ as the standard notation (not just because its easy to type nCk). For example, this website:…
user71207
  • 1,543
2
votes
2 answers

What does $|$ mean?

I came across this notation in a solution manual. It appears in the solution to Exercise 1.2.2. as $3|2^p$. Any idea what it could mean?
Undertherainbow
  • 760
2
votes
0 answers

What does x ∈ {0, 1}* mean?

I was reviewing some papers and came across the notation x ∈ {0, 1}* I want to know what it means. Thank you! Edit: I noticed I did not put enough context to the question. The paper I reviewed was about blocks in a blockchain. It states: "A block is…
avocadojuice08
  • 21
2
votes
0 answers

Correct position of equal sign in multiline equation

An equation on a piece of paper is too long for a single line and needs to be split into two lines. The equal sign happens to be at the line break. Does the equal sign belong at the end of the first line, or the beginning of the second line?
reggie
  • 123
  • 3
2
votes
1 answer

Symbol for cover

Is there a symbol for the cover operator? Given two family of sets(lets say $\mathcal{A}$ and $\mathcal{B}$) $$ \mathcal{A} = \{A_1, A_2, ..., A_m\}$$ $$ \mathcal{B} = \{B_1, B_2, ..., B_n\}$$ $\mathcal{A}$ covers $\mathcal{B}$ iff the following…
Jayitha Reddy
  • 105
2
votes
0 answers

A question about notation in a definition

I am writing a paper in which I give the following definition. Let $n$ be a natural number greater than or equal to $2$. Define a function $f_n:[0,1]\to\mathbb{R}$ by $$ f_n(c)=\sup\{\|P_n...P_2 P_1-P_0\|\,|\,c_F(H;H_1,...,H_n)\leqslant…
Ivan Feshchenko
  • 234
2
votes
1 answer

A question about the validity of a notation

I am writing a paper and using such a notation. Do you think that it is mathematically a reasonable notation? $$ \hat{{\cal{P}}}_{i}=\{\hat{Q}: \hat{Q}_i|G_i[q_1/q_0
Seyhmus Güngören
  • 7,848
2
votes
2 answers

How can I express that a symbol $f_\alpha$ is contextually associated with a symbol $\alpha$ but without implying that $f_\alpha$ depends on $\alpha$?

Lets say I have the two symbols $\alpha$, $\beta$ and another two symbols, which are contextually associated with $\alpha$, $\beta$. For example $a$, $b$ as factors for a formula $a \cdot \alpha + b \cdot \beta$. From a notation point of view, how…
kostrykin
  • 475
2
votes
1 answer

Modulo operation notation

I would like to write that some polynomial $p(x)$ is the sum of polynomial $d(x)$ and the remainder of division of polynomial $b(x)$ by polynomial $w(x)$: $$p(x) = d(x) + b(x)\bmod w(x)$$ But from what I saw in books, this can mean something…
scdmb
  • 369
2
votes
0 answers

When should the first letter of an abbreviated function be capitalised?

Many functions in mathematics are denoted using abbreviated names. However, the capitalisation of these function names seems to be inconsistent to me: functions like $\sin$, $\cos$ and $\exp$ are all lowercase, whereas $\mathrm{Re}$ and…
DavidH
  • 151
2
votes
2 answers

Notation of max?

What does the following notation mean? $$V^{(k)}(s) = \max_{a \in A} \sum_{s' \in S}T(s,a,s') [R(s,a,s') + \gamma\cdot V^{(k-1)}(s')]$$ Does it mean max the value of the function with a element of A. What will be the result of the Function a element…
Hans Mustermann
  • 35
2
votes
1 answer

What is the use of caligraphic characters in mathematics?

The only one I am familiar with is $\mathcal{L}$ for Laplace transforms, but I have now encountered other symbols such as $\mathcal{F}$ and $\mathcal{M}$. I'm curious: does each calligraphic letter have a specific use case, or are they just…
Kalcifer
  • 558
2
votes
1 answer

Is there a formal name for an "undecorated" variable?

That is, is there a term to specifically distinguish the type of thing x is, as juxtaposed with x', x'', etc? The wikipedia page on the prime symbol mentions that "The prime is said to "decorate" the letter to which it applies.", which gives me that…
Personman
  • 121
1 2 3
…
99 100