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: Stefan Berghofer, TU Muenchen
#
# DESCRIPTION: display Isabelle version
echo 'unidentified repository version' # filled in automatically!