Donald Bren School of Information and Computer Sciences

A schema is defined for characterising flowchart programs. This schema is used to construct a procedure for generating the set of flowcharts which contain n branching tests but which are irreducible; i.e., have no embedded flowcharts. The sets of such flowcharts for n ≤ 4 are enumerated here. Some examples from these sets are discussed. Suggestions are made concerning the utility of these flowcharts in the analysis of goto-less programming and in gaining insight into potential programming language constructs. A proof of the procedure for generating irreducible flowcharts is given.