(cd $(DISTDIR) && find . -name .depend.opt -exec rm \{\} \;)
(cd $(DISTDIR) && rm -rf $(CLEAN_ON_DIST))
cp $< $(DISTDIR)/configure
+ cp dist/configure.ac $(DISTDIR)/configure.ac
cp -r $(EXTRA_DIST) $(DISTDIR)
cp -r $(EXTRA_DIST_matita) $(DISTDIR)/matita
# distribute HTML version of the manual