proper symbol markup with \isamath, \isatext;
support sub/super scripts:
## $Id$# Author: Markus Wenzel, TU Muenchen# License: GPL (GNU GENERAL PUBLIC LICENSE)## Isabelle user settings sample (everything commented out)# -- may be copied to ~/isabelle/etc/settings#ISABELLE_USEDIR_OPTIONS="-i true -d pdf"ISABELLE_LOGIC=HOL