slightly more standard data merge: Symtax.merge (K true) avoids equality on abstract type Pretty.T and gracefully accepts overriding, Symtab.join prefers first entry as usual;
#!/usr/bin/env bash
#
# Author: Makarius
#
# DESCRIPTION: simple XML to YXML converter
PRG="$(basename "$0")"
function usage()
{
echo
echo "Usage: isabelle $PRG"
echo
echo " Convert XML (stdin) to YXML (stdout)."
echo
exit 1
}
function fail()
{
echo "$1" >&2
exit 2
}
## process command line
[ "$#" -ne 0 ] && usage
## main
exec "$ISABELLE_HOME/lib/scripts/yxml"