Computing answers in default logic
R.A.T. Guerreiro, A. Silva, Marco A. Casanova · 2003
A class of logic programming systems based on R. Reiter's (1980) default logic is discussed. The first question addressed is how to compute answers when a query is a set of clauses and a program is a set of clauses and defaults. The clauses are not restricted to be Horn clauses and the defaults are a special case of Reiter's open normal defaults. Then, the problem of computing answers is discussed in the context of the concept of typical elements. This concept of typicality is carefully defined and given a clean semantics.>