Paraconsistent information is information that is incomplete and/or inconsistent. A data model for representing and manipulating
paraconsistent information in relational databases has recently been developed. Algebraic operators on the underlying paraconsistent
relations of this model are generalizations of the usual ones on ordinary relations. However, unlike in the ordinary case,
a DBMS based on paraconsistent relations must be capable of handling infinite relations. In this paper, we show this necessity
and identify classes of infinite paraconsistent relations whose members can be effectively represented and manipulated. We
show that the classes of REGULAR and, under different conditions, CONTEXT-SENSITIVE as well as PSPACE paraconsistent relations
are such. We also show that the CONTEXT-FREE and R.E. classes do not have the desired properties, while P, NP, LOGSPACE and
NLOGSPACE also probably do not. These results help identify the kinds of relational DBMS that can be constructed for handling
incomplete and inconsistent information about tuples.
Abstract This research has been partially supported by the National Science Foundation research grant no. IRI 96-28866.