Questions tagged [notation]
For questions about the history and development of how symbols and related objects are written.
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When was the symbol "U" first used to denote voltage or electric potential difference?
It is said that the symbol U for voltage was first introduced in the German literature, and is short for "Unterschied", that is "difference".
Before a distinction between "...
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Who is the first to use $\cong$ to denote isomorphism?
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In mathematics, especially in model theory and algebra, people usually use $\cong$ to denote isomorphism, but who is the first to do so? Someones also use $\simeq$ instead and who is the ...
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Who is the first to use $\approx$ to denote "approximately equal"?
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Nowadays many people use $\approx$ to denote "approximately equal". In wikipedia, it says, $\approx$ was introduced by British mathematician Alfred Greenhill in (1892, Applications ...
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Who decided to use (a, b) for open intervals and [a, b] for closed intervals, and why?
The use of $$(a,b)$$ as an abbreviation for $$\{x\in\Bbb R\mid a<x<b\}$$
and $$[a,b]$$ as an abbreviation for $$\{x\in\Bbb R\mid a≤x≤b\}$$ is so widespread and so entrenched that I was surprised ...
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Who is the first to use $\{,円\}$ to denote the empty set?
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Many people use $\{,円\}$ to denote the empty set (see wikipedia), but who was the first to do so? From the link, Frege uses $\{,円\}$ to denote the empty set, but I don't find such uses in ...
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Square root defined as a positive value: why?, when? who?
In the Mathematics Educators Stack Exchange, a poster asked whether $\sqrt 4$ could be considered as both $+2$ and $-2$. However, in modern mathematics, $\sqrt 4$ is conventionally defined as $+2$. I ...
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What are the origins of the symbols used to denote levels of the arithmetic hierarchy?
The arithmetic hierarchy is a method of classifying the complexity of problems by treating such problems as logical formulas and organizing them according to the quantifiers they contain. There are ...
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Was there a special reason for using $j$ as the marker for nontrivial elementary embeddings?
In set theory, there are these functions called "nontrivial elementary embeddings" which can be used as introduction parameters/"generators" of various large cardinals and similar ...
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Why is $p$ used for momentum?
Wikipedia says that $p$ comes from the Latin pellere (meaning "push" or "drive"). This book by Talagrand says $p$ comes from the Latin pulsus (page 37, footnote 34). I've also ...
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Why is bar notation ($\bar{x}$) preferred over square brackets ($[x]$) for quotient rings?
In abstract algebra, when dealing with quotient rings ($R/I$), it's common to use bar notation $\bar{x}$ to represent cosets, rather than square brackets ($[x]$) or other notations.
Is there a ...
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Who firstly used ≣ as "strictly equivalent to"?
As in the link and the link the UTF character 2263 "≣" is used as "strictly equivalent to" ($\phi$ is strictly equivalent to $\psi$ iff $\phi$ strictly implies $\psi$ and $\psi$ ...
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Why are powers of a thousand the foundation for naming large numbers?
In our modern number system, large numbers are named based on powers of one thousand. For example, "thousand", "million", "billion", and so forth. Numbers in between ...
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Why are Chebyshev polynomials denoted by the letters $T_n$ and $U_n$?
According to wikipedia, Chebyshev polynomials were first presented in his paper Théorie des mécanismes connus sous le nom de parallélogrammes (1854), but the notations $T_n$ and $U_n$ don't seem to ...
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Equality by definition symbol
Since when is the symbol $x := y$ (for "$x = y$ by definition") used in mathematics?
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Natural Deduction, question on Gentzen notation
Can anyone explain the function of the brackets, curved tent like A and C in this picture? Specifically forms EB, FE, and NE? These are eliminationright?
This page explains some of the notation so it ...