--- a/model/grammar/yack/prov-n-LL.bnf	Tue Jun 12 12:12:50 2012 +0100
+++ b/model/grammar/yack/prov-n-LL.bnf	Tue Jun 12 16:22:41 2012 +0100
@@ -80,16 +80,19 @@
 
 
 
-[28] insertionExpression::=	"derivedByInsertionFrom" "("  optionalIdentifier cIdentifier "," cIdentifier "," keyEntitySet optionalAttributeValuePairs ")"
+[28] insertionExpression::=	"derivedByInsertionFrom" "("  optionalIdentifier dIdentifier "," dIdentifier "," keyEntitySet optionalAttributeValuePairs ")"
 
 
 [29]keyEntitySet::= "{"  "(" literal "," identifier  ")" ( ","  "(" literal "," identifier  ")" )* "}"
 
-[30] removalExpression::=	"derivedByRemovalFrom" "("  optionalIdentifier cIdentifier "," cIdentifier "," keySet optionalAttributeValuePairs ")"
+[29]entitySet::= "{"   eIdentifier *  "}"
+
+[30] removalExpression::=	"derivedByRemovalFrom" "("  optionalIdentifier dIdentifier "," dIdentifier "," keySet optionalAttributeValuePairs ")"
 
 [30a] keySet::= "{" literal ("," literal)* "}"
 
-[31] membershipExpression::=	"memberOf" "("  optionalIdentifier  cIdentifier "," keyEntitySet complete  optionalAttributeValuePairs ")"
+[31] membershipExpression::=	"memberOf" "("  optionalIdentifier  dIdentifier "," keyEntitySet complete  optionalAttributeValuePairs ")"
+| 	"memberOf" "("  optionalIdentifier  cIdentifier "," entitySet complete  optionalAttributeValuePairs ")"
 
 [31b] complete::= ("," ("true" | "false" | "-"))?
 
@@ -104,6 +107,7 @@
 agIdentifier ::=identifier
 gIdentifier ::=identifier
 uIdentifier ::=identifier
+dIdentifier ::=identifier
 cIdentifier ::=identifier
 bIdentifier ::=identifier