proper symbol markup with \isamath, \isatext;
support sub/super scripts:
#!/bin/bash## $Id$# Author: Markus Wenzel, TU Muenchen# License: GPL (GNU GENERAL PUBLIC LICENSE)## DESCRIPTION: translate symbols into \<...> sequences#set by configureAUTO_PERL=perlexec "$AUTO_PERL" -w "$ISABELLE_HOME/lib/scripts/symbolinput.pl" "$@"