[XeTeX] genotype

[Michael Sharpe]

On Jan 1, 2012, at 10:46 AM, Jean-Louis Cordonnier wrote:

> In order to write genetics, I need something like $\frac{A}{a}$ but with
> a double horizontal bar -- and left( and right)
> I tried this, but there is too much white around it.
> 
> \newcommand\gen[2]{ %genotype
> 
> $
> 
> \left(
> 
> \begin{array}{c} #1 \\
> 
> \hline \hline #2\\
> 
> \end{array}
> 
> \right)
> 
> $
> 

You can reduce the white space inside the parentheses using a negative mkern. Eg,

\newcommand\gen[2]{ %genotype
$
\left(\mkern-4mu
\begin{array}{c} #1 \\
\hline \hline #2\\
\end{array}
\mkern-4mu\right)
$}

Michael