I'm trying to use this symbol in a LaTeX document I'm writing but I can't for the life of me, find how to write it in LaTeX:
The symbol means that two expressions are logicically equivalent (i.e. A |==| B)Can anybody identify the missing symbol?
[Tex/LaTex] Symbol for logical equivelence
math-modesymbols
Related Solutions
Note that the document uses Springer's LNCS style. In this style, all Greek letters are in italics, and vectors are denoted by boldface.
Most likely the bold italic Delta is produced in this particular case by something similar to this:
\documentclass{llncs}
\begin{document}
$\vec{\Delta}$
\end{document}
The result is:
Note that if you used the article class, the same code would produce a normal Delta with an arrow:
Package colonequals provides a vertically centered colon: \ratio. Both \ratio and \Leftrightarrow are of kind \mathrel, therefore TeX will not put additional space between them:
\documentclass{article}
\usepackage{colonequals}
\newcommand*{\logeq}{\ratio\Leftrightarrow}
\begin{document}
\[ A \logeq B \]
\end{document}
When additional space is wanted between the colon and the arrow (see Raphaels's comment), then \colonsep can be defined and set between the symbols, e.g.:
\renewcommand*{\colonsep}{\mkern1mu\relax}% small extra space
\newcommand*{\logeq}{%
\mathrel{\ratio\colonsep\Leftrightarrow}%
}
P.S.
It does not matter here, whether the star form of \newcommand is used or not, because there aren't any argument and the definition is not empty. Therefore it is mostly a matter of taste here.
I prefer the star form, because I am thinking rather in terms of lower level commands. \newcommand* uses \def, whereas \newcommand uses \long\def. Without arguments I do not see a reason for \long, therefore I am using \newcommand*.
Best Answer
Without the use of packages, you could do this:
If you didn't like the height of the
\verts, you could do this instead: