# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
-# Tactics for dealing with URLs. These require the curl command
+# Predicates for dealing with URLs. These require the curl command
# line tool.
-# XXX tactic *url
+# XXX predicate is-url
# Check only if a URL exists without considering its age.
-tactic *url_exists (url) = {
+predicate is-url-exists (url) = {
curl --output /dev/null --silent --head --fail %url || exit 99
}