# Questions tagged [notation]

For questions about mathematical notation, i.e. the symbols used to represent mathematical objects and operations.

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### Does $\mathsf{SVC}^\ast$ exist?

$\mathsf{SVC}(S)$ is the assertion that for all sets $X$ there is an ordinal $\eta$ and a surjection $f\colon\eta\times S\to X$. I would like to denote by $\mathsf{SVC}^\ast(S)$ the same assertion but ...
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### How to talk about the “shape” of the kernel of an integral transform

So I'm learning about integral transforms, and although it isn't a complete specification, the fact that the Fourier transform decomposes functions into sinusoids, the Laplace into damped sinusoids, ...
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### Notation for weak derivatives

I remember that, as a student, I felt a bit uncomfortable because I had to use the same notation (say $f'$, $D^\alpha f$, $\frac{\partial f}{\partial x^j}$, $\nabla \cdot f$ etc...) for classical and ...
110 views

What are the reasons for the adjunction symbol $F\dashv G$ for a pair of functors $F:C\to D$ and $G:D\to C$? There is no explanation or motivation in the article of Kan where adjunctions are ...
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### Notation $\le_{a,b,n,\ldots}$ in Analysis

In modern Analysis, especially Functional Analysis, one proves, or one uses inequalities of the form $$F(X)\le_{a,\ldots,n}G(X).$$ The meaning of the subscripts in the inequality sign means that there ...
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### Pronunciation: the Erdős–Rado partition notation

The Erdős–Rado notation $a \rightarrow (b)^c_d$ is common in partition calculus / combinatorial set theory, as well as its negation $a \not\rightarrow (b)^c_d$. In that field, is there a standard way ...
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### Reference request: Different definitions of Big O notation

This question might sound strange, but I would like to settle this problem once and for all. For as long as I can remember, I was introduced to the Big O notation by this definition: Def. 1: Let $f, g$...
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### Terminology and notation for generated subgroups

I would like to think about formation of the smallest subgroup (or monoid, or whatever) $H$ of $G$ containing two given subgroups $A$ and $B$ as an operation on subgroups, and I wonder if there is a ...
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### Higher order Leibniz rule and ordered multiindex notation

Although I think this is probably known, I am making here a short exposition on the multiindex notations I am using to make this question self-contained. I note that there is at least two different ...
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1 vote
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### What does square bracket superscript star mean in basic group theory typically?

I'm reading some paper where they haven't really defined their notation very well (or I've missed something). You can see the image below. What does the square bracket and star mean precisely? The ...
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### Notation for H is isomorphic to a subgraph of G

Is there a notation for the statement $H$ is isomorphic to a subgraph of $G$? I was thinking of using $H<G$, but I'd like to use standard notation if possible.
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### Proof of Theorem 9.2 of the book Cubic Forms by Yu. I. Manin (end of page 37)

I warn that I first posted this question in Mathematics Stack Exchange but it got no attention at all. I think that it fits better there by its explanatory nature but maybe the book being reference is ...
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### Finitely-generated conjugation action on a subgroup that is not normal... what is that?

If $H \lhd G$, then $G$ acts on $H$ by conjugation. I need to talk about this action but in a situation where $H$ is not (necessarily) normal. When $H \leq G$, there is a "partial action" of ...
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### How to denote a partial derivative?

This question is related to Was Jacobi the first to notice the ambiguity in the partial derivatives notation? And did anyone object to his fix? and Suggestions for good notation . When there are two ...
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### Good notation for finite partial functions from $\omega$ to 2

I'm working in computability theory and need to use partial functions with finite domain from $\omega$ to 2 as approximations in my current paper. Normally this is simply done using $2^{< \omega}$ ...
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