Sets and graphs in GRAAL

This paper is an attempt at presenting a high level model of the set and graph aspects of the graph algorithmic language GRAAL [5]. The problem area for which the language GRAAL was designed was the solution of graph problems of the type primarily arising in applications. It was designed with two objectives in mind. The first was to develop a language which permitted the writing of graph algorithms in a highly readable form with as natural a set of primitives as possible for describing the algorithm. The second was to allow for a wide variety of graphs of different types and complexity with as little degradation as possible in the efficient implementation and execution of an algorithm designed for a specific type of problem.