CSSE 373 -- Formal Methods in Specification and Design

                                Quiz 9



Name:_________________________________________    Grade:______________


1. Given the declarations:

		abstract sig Object { }
		sig Directory extends Object { ... }
		sig File extends Object { }
		sig Alias extends File { ... }


   in the command
		
		run show for exactly 3 Directory, exactly 3 Alias, 5 File
	
   how many total objects would be generated if we added "exactly"
   before "5 File"?  (Careful.  Alias and File are related.)






2. Rewrite the Alloy model below to not use a Boolean type.

	sig Lift {
		goingUp: Time -> Boolean,
		goingDown: Time -> Boolean
	}