Entity sorts: what are they? (English) Zbl 0633.03002

This is an explication of the terms “entity set” and “value set” as introduced by P. P. S. Chen [ACM Trans. Database Syst. 1, 9-36 (1976)] (“entity sort” and “descriptive sort” being used instead in the HIT data model [see J. Zlatuška: HIT data model. In: Proc. VLDB ’85, Stockholm (1985)]). It is shown that entity sorts can be represented (in databases) by means of descriptive sorts only, since an entity sort is always given through a property, i.e., through an intension, unlike descriptive sorts which are recursive classes.


03A05 Philosophical and critical aspects of logic and foundations
03B65 Logic of natural languages
68P05 Data structures
68Q55 Semantics in the theory of computing