1. Describe, in both an operational style and a descriptive style, the fact that a fixed number of processes can access any of a fixed number of common resources in mutual exclusion. Compare the two specifications. 2. Write a paper comparing the specification of with the specification of from several points of view. 3. Here is an example of a real-time specification that does not involve mission-critical systems (it has been mentioned in With many computer windowing systems, the user may click or double-click the mouse. If two clicks occur within a given time At, their meaning is different from the case in which they are separated by a longer interval. Describe the Macintosh click and double-click semantics both in an operational (e.g., by means of timed PNs) and in a logic style. Compare the two specifications.