--- a/src/HOL/HOLCF/Plain_HOLCF.thy Tue Apr 04 21:44:44 2017 +0200
+++ b/src/HOL/HOLCF/Plain_HOLCF.thy Tue Apr 04 21:45:54 2017 +0200
@@ -12,6 +12,4 @@
Basic HOLCF concepts and types; does not include definition packages.
\<close>
-hide_const (open) Filter.principal
-
end