Abstract
Starlog, a Horn clause logic programming language, allows for time stamps,
interval arithmetic, and negations. A bottom-up evaluation strategy, called
"Time-ordered Forward Deduction", for the language is described. The
algorithm heavily relies on time stratification as its basic execution
control mechanism. A conservative approach has been adopted to handle
negations, which defers the evaluation of negations until it is safe to do so.
Various techniques to deal with subtle cases of inter-clause relations in
negation evaluation are discussed. To illustrate the algorithm, some simple
but non-trivial example programs are presented.
