<!ELEMENT LetVIn (%stringsetexpr;, Vtarget)>
-<!ELEMENT Relation (Refine?,%setexpr;, Attr+)>
+<!ELEMENT Relation (PName?,%setexpr;, Attr+)>
<!ATTLIST Relation
- name CDATA #REQUIRED>
+ name CDATA #REQUIRED
+ refine (sub|super) #IMPLIED>
<!ELEMENT Union (%setexpr;, %setexpr;)>
<!ATTLIST Attr
binder CDATA #REQUIRED>
-<!ELEMENT Refine (SUB|SUPER|CONST+)>
+<!ELEMENT PName (CONST+)>
<!-- MathQL boolean expressions -->