use THIS

DBEngine.h

@@ -45,7 +45,7 @@ public:
 	bool unionComp(Relation r1, Relation r2) { 
 		//Two relations are union-compatible if they have the same # of attributes and each attribute must be
 		//from the same domain
-		
+		//return (() && ());
 	}
 	
 	

Relation.h

@@ -6,7 +6,7 @@
 class Relation {
 	string name; //The title the user gives it
 	vector<Attribute> att; //A vector of the columns
-	itn size;
+	int size;
 	
 public:
 	Relation(string n, vector<Attribute> a) {