In this paper we consider the problem of teaching systems programming and software design. We point out some of the major faults of many courses in this area and propose a course structure and method of presentation which we feel overcomes these faults. We review our past experience in using the proposed method and point out some aspects which need further development.

In this paper we will define and discuss a solution to some of the problems concerned with protection and security in an information processing utility. This paper is not intended to be an exhaustive study of all aspects of protection in such a system. Instead, we concentrate our attention on the problems of protecting both user and system information (procedures and data) during the execution of a process. We will give special attention to this problem when shared procedures and data are permitted.

This paper describes an algorithm for scanning Boolean expressions.Such an algorithm takes a complex, relational expression and transforms it into an optimal set of computing steps.The result is optimal in the sense that no redundant evaluations are made.The particular algorithm described is advantageous in that, as a variant of a well-known *