Update doc/src/sections/hiopbbpy.tex

Co-authored-by: Nai-Yuan Chiang <chiang7@llnl.gov>

Author: cnpetra

doc/src/sections/hiopbbpy.tex

@@ -21,7 +21,7 @@ \subsection{HiOpBBpy installation}
 
 \Hibbpy also supports using nonlinear optimization solver Ipopt \cite{ipopt_impl} as its internal solver. 
 In order to use Ipopt, \Hibbpy optionally depends on {\it{cyipopt}}, which is a Python wrapper of Ipopt.
-To use Ipopt via {\it{cyipopt}},, one can install Ipopt from source, and then export the \verb~IPOPT_PATH~ and 
+To use Ipopt via {\it{cyipopt}}, one can install Ipopt from source, and then export the \verb~IPOPT_PATH~ and 
 \begin{verbatim}
 > export PKG_CONFIG_PATH=$PKG_CONFIG_PATH:$IPOPT_PATH/lib/pkgconfig
 > export PATH=$PATH:$IPOPT_PATH/bin