CSSE 373 -- Formal Methods in Specification and Design

                                Quiz 3



Name:_________________________________________    Grade:______________


1. Relations in Alloy are a lot like tables in relational databases, but not
   exactly the same.  List three ways in which relations and Alloy differ:
   
   	* 
   	
   	
   	
   	*
   	
   	
   	
   	*
   	
   	
   	
2. Are the following two relations equivalent? _______

	* { (N0, D0), (N1, D1), (N2, D2) }
	
	* { (N1, D1), (N2, D2), (N0, D0) }


   Why or why not?
   
   
   
   
   
3. Are the following two relations equivalent? _______

	* { (N0, D0), (N1, D1), (N2, D2) }
	
	* { (D0, N0), (D1, N1), (D2, N2) }


   Why or why not?
   




4. What's the difference between sets in Alloy and the usual sets in Math?





5. What is a "scalar"?





(continued on back)






6. Why does Alloy use relations for almost everything?







7. What does it mean when we say Alloy doesn't allow higher-order relations?  
   






8. Of the three styles of writing constraints in Alloy, which is the preferred
   style and why?