--- a/src/CTT/CTT.thy Sun Sep 12 20:09:36 2021 +0200
+++ b/src/CTT/CTT.thy Sun Sep 12 20:11:20 2021 +0200
@@ -304,9 +304,9 @@
ML \<open>
local
-fun is_rigid_elem (Const(\<^const_name>\<open>Elem\<close>,_) $ a $ _) = not(is_Var (head_of a))
- | is_rigid_elem (Const(\<^const_name>\<open>Eqelem\<close>,_) $ a $ _ $ _) = not(is_Var (head_of a))
- | is_rigid_elem (Const(\<^const_name>\<open>Type\<close>,_) $ a) = not(is_Var (head_of a))
+fun is_rigid_elem \<^Const_>\<open>Elem for a _\<close> = not(is_Var (head_of a))
+ | is_rigid_elem \<^Const_>\<open>Eqelem for a _ _\<close> = not(is_Var (head_of a))
+ | is_rigid_elem \<^Const_>\<open>Type for a\<close> = not(is_Var (head_of a))
| is_rigid_elem _ = false
in