diff --git a/dataspace-patterns.prs b/dataspace-patterns.prs
index 2740763..bfba3ad 100644
--- a/dataspace-patterns.prs
+++ b/dataspace-patterns.prs
@@ -6,6 +6,10 @@ Pattern = DDiscard / DBind / DLit / DCompound .
 DDiscard = <_>.
 DBind = <bind @name symbol @pattern Pattern>.
 DLit = <lit @value any>.
-DCompound = @rec  <compound <rec @label any @arity int> @members { int: Pattern ...:... }>
-          / @arr  <compound <arr @arity int>            @members { int: Pattern ...:... }>
-          / @dict <compound <dict>                      @members { any: Pattern ...:... }> .
+DCompound = @rec  <compound @ctor CRec  @members { int: Pattern ...:... }>
+          / @arr  <compound @ctor CArr  @members { int: Pattern ...:... }>
+          / @dict <compound @ctor CDict @members { any: Pattern ...:... }> .
+
+CRec = <rec @label any @arity int>.
+CArr = <arr @arity int>.
+CDict = <dict>.