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: invoke Scala within the Isabelle environment
[ -z "$SCALA_HOME" ] && { echo "Unknown SCALA_HOME -- Scala unavailable"; exit 2; }
[ -e "$ISABELLE_HOME/Admin/build" ] && { "$ISABELLE_HOME/Admin/build" jars || exit $?; }
CLASSPATH="$(jvmpath "$CLASSPATH")"
exec "$SCALA_HOME/bin/scala" "$@"