Is there a preferred way to typeset an empty sqrt? What I'm doing now is \sqrt{\phantom{a}}, are there other/preferred ways like a standalone symbol? Or should I just create a new macro with the phantom a?
[Tex/LaTex] Typesetting an empty square root
symbols
Related Solutions
Both txfonts and bbold declare the math alphabet \mathbb, therefore the first definition is overwritten by the package which is loaded last. If you generally want to use the txfonts blackboard bold symbols, you can declare a new math alphabet \mathbbold instead of loading bbold:
\documentclass{article}
\DeclareMathAlphabet{\mathbbold}{U}{bbold}{m}{n}
\usepackage{txfonts}
\begin{document}
\[
\mathbbold{1}, % from bbold
\mathbb{N} % from txfonts
\]
\end{document}
I recommend using a vertically centered colon which matches the equal sign better, such as \vcentcolon from the mathtools package. You can also change it generally to vertical by \mathtoolsset{centercolon}.
Compare standard :=
to the vertically centered:
So your definition could become
\usepackage{mathtools}
\newcommand{\defeq}{\vcentcolon=}
\newcommand{\eqdef}{=\vcentcolon}
with tighter spacing. And since both symbols are already relation symbols, as egreg said, we even could omit \mathrel.
And you could do that even easier by mathtools provided commands:
\documentclass{article}
\usepackage{mathtools}
\begin{document}
$a\coloneqq b \qquad b\eqqcolon a$
\end{document}
Best Answer
The
\surdcommand just produces the radical symbol √ as opposed to\sqrt{stuff}which typesets the square root ofstuffwith a bar overstuff. The Chicago Manual of Style uses just the radical symbol in the text "The radical sign √ is used to denote the square root".The Penguin Dictionary of Mathematics also just uses the radical sign (without an over bar) when defining both the terms "radical" and "square root".