Use the convention tag for questions about standard, cultural practices in mathematics.

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5
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1answer
70 views

The convention for speakers to refer to themselves at the board with a single initial

This question is being asked on behalf of a graduate student in my department. When and where did the tradition start of a seminar or colloquium speaker using just the first initial of the speaker's ...
2
votes
1answer
118 views

Which is the best notation for a sequence?

In a set, the order of its elements is (as far as I know) not important; in a sequence, the order of its elements is important. Which is the notation I should use in order to define a sequence? I ...
0
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1answer
67 views

Name and notation convention for “unnormalized probability”

Given a finite set of non-negative numbers $S={s_1,...,s_n}$, we can divide them by a normalization constant $Z$ (i.e. their sum) to get a probability distribution. Then we typically say (and write) ...
0
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1answer
33 views

Value expressions

What is the value of the expression: $\sum_{k=0}^{d}b^{k}\left[\begin{array}{c} d\\ k \end{array}\right]\prod_{i=0}^{k-1}\left(c-b^{i}\right) $ for $ k = 0 $? In particular, what is then the value ...
2
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0answers
57 views

Does typesetting of mathematical content differ in right-to-left languages?

Languages such as Arabic or Hebrew are written right-to-left. Does the way mathematical content is written differ in those languages? Some simple examples of which I would be interested to know how ...
2
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0answers
37 views

Einstein summation convention

I am not sure how to expand the following expression with regard to the Einstein summation convention. More specifically, I have: \begin{equation} a_{ij} = b_{i, j} + b_{j, i} + c_{ij, kk} \\ c_{ij} = ...
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0answers
13 views

Unit rules and style convention for division

I'm trying to figure out the preferred way to write unit expressions and division is causing me some confusion. I'm aware of the negative exponent notation, but here I'm looking for a solution using ...
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0answers
17 views

How to write upper and lower generic limits of a definite integral

I have an integral whose upper and lower limits depends on the probabilty distribution chosen for the variable, $x$, I am integrating on. For example, if I consider that $x$ is normally distributed ...
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0answers
30 views

The simply connected form of a semisimple algebraic group

Let $G$ be a semisimple algebraic group over an algebraically closed field $k$, so that $G$ is an almost-direct product of its minimal closed connected normal subgroups of positive dimension, ...
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0answers
11 views

Symbol or name for Basismatrix of Linear Programming

This question is about the Basismatrix in the context of Linear Programming. Basically (haha!) we have the Matrix of the standard (or normal) form, which consists of (A|E) with the coefficient matrix ...
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0answers
37 views

problems on define set with polynomials

I'm trying to say set A is the set of nonnegative integers that not of this two forms $3x^2 + (6y-4)x - y\ $ and $\ 3x^2 + (6y-2)x + (y - 1)$, for example: $4=3 \cdot1^2+(6 \cdot1-4) \cdot 1-1\ $ is ...
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0answers
39 views

Graph diameter of a single vertex?

Convention-wise, given the simple graph with a single vertex, what is the graph diameter? I can see three options, zero, since there is a trivial path from the vertex to itself. infinity, since ...
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0answers
41 views

shouldn't we specify the topology when we talk about Borel $\sigma$-algebras?

Maybe this is me being pedantic, but this thought has just occurred to me. The Borel $\sigma$-algebra on X is the smallest $\sigma$-algebra containing all open sets. When we talk about Borel ...
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0answers
105 views

Convention on the order of scalar multiplication (Multiplier vs multiplicand)

Is there a convention on the order of scalar multiplication? I know there were questions before mine, but I would like to know if such distinction is culturally dependent. This came from a news in ...
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0answers
62 views

decimal digit grouping delimiters

I feel a bit silly having to ask this but I just can't seem to find any resources that give an answer to this. When dealing with decimal values that have a large number of digits to the right of the ...
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0answers
57 views

Matrix with rank more than $1$

Is there a shorter way of saying that a matrix $A$ has rank more than $1$? I am looking for something like "full-rank", or "rank-deficient."
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0answers
71 views

Canonical way of denoting the set of all (totally) ordered subsets

Given a finite set $S$, we usually denote the set of all subsets of $S$ by $\mathcal{P}(S)$, i.e. the power set of $S$. I need to denote the set of all totally ordered subsets of $S$, let us call it ...
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0answers
18 views

What is the appropriate way to indicate that a long statement is continued on the next line?

When handwriting a long mathematical statement or equation, what is the clearest way to indicate that it is continued on the next line uninterrupted? I've considered defining a variable to equal ...
0
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0answers
22 views

Is is possible to define a sign convention for eigenvectors calculated with a small uncertainty?

I'm working with a numerical method that involves the diagonalization of a real, symmetric $n \times n$ matrix $H$. Now obviously the sign of the (normalized) eigenvectors $\phi_i$ is not well ...
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0answers
55 views

How to show proper set inclusion/exclusion? Please don't give me the solution.

I found this problem from an online source. I've just got two question 1) I think there is a typo in the solution, it should be $(x_n) \in \ell_1$ right? 2) I am guessing $c_0 \subsetneq ...
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0answers
40 views

Are there official names for these functions?

$\newcommand{\sgn}{\operatorname{sgn}}$ Does anyone know if the simple function $$ y(x)=x^2\sgn(x)$$ or alternately $$ y(x)=x|x|$$ has any (official) name in mathematics or engineering? or ...
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0answers
41 views

Given a set of rotation matrices, is it possible to determine the rotation conventions employed?

Given three rotation matrices, is it possible to determine the conventions used in defining them? These conventions include: passive or active transformation, pre- or post-multiplication, right- or ...