\def\bp{\widehat{\gamma}}% a billiard path
\def\D{{\mathcal D}}% double of a triangle \D(T)
\newcommand{\Param}{\Delta}% the parameter space of triangles
\def\MT{\textrm{MT}}% minimal translation surface
\newcommand{\tri}{T}% a triangle
\newcommand{\UAC}{\textrm{UAC}}% the universal abelian cover.
