The METANET referred to in this paper is simply a schema for directed graphs with labels on both the arcs and nodes. The paper specifies the schema as an abstract data type with a set of conditional rewrite rules of the form p & {cond} :2WZ q, meaning that expression p can be rewritten as q if condition cond is true. (This notation is not properly explained in the paper.) A proof that the set of rules is well-behaved (noetherian and confluent) is given. As illustration, the METANET specification is instantiated to describe a “semantic net” having concept and instance nodes, and elementof and subsetof arcs. This takes 78 rewrite rules. Finally, the METANET specification is extended to include spaces along with the arcs and nodes. This is supposed to illustrate specification of the partitioned networks introduced by Hendrix [1].

This paper may be of some interest to abstract data type buffs, but it holds no interest to those who actually want to implement semantic networks. In some ways, labeled graphs are simpler to specify than stacks and queues, and no one will have difficulty in implementing them correctly. The features that distinguish semantic nets from labeled graphs, an inheritance hierarchy, and other built-in inference mechanisms, are not even mentioned in this paper.