an alternative FCB for Abs_lst1; seems simpler but not as simple as I thought; not sure whether it generalises to multiple binders.
\documentclass[14pt,t]{beamer}
%%%\usepackage{pstricks}
\input{root.tex}
%%% Local Variables:
%%% mode: latex
%%% TeX-master: t
%%% TeX-command-default: "Slides"
%%% TeX-view-style: (("." "kghostview --landscape --scale 0.45 --geometry 605x505 %f"))
%%% End: