1 Logic Programs and a New

ABSTRACf We propose a methOd of parallelizing bottortl-up-evaluation of logic programs. The method is distinguished by the fact that it is pure i.e., does not require inU7procesSor communication, <r synchronization overhead The method cannot be used to parallelize every logic program, but we syntactically charac~erize several classes pf logic programs to which the method can be applied (e.g., the class of linear single rule programs). We also provide a characterization for a class ofv.rograrns to which the paralleliza-tion m~th,od cannot be applied, and s~ow that in ge,neral, determining aPPlicability is undecidable. 'lben, we generalize the concepts beyond the proposed method, and "lay the foundations for a theOry of logic programs and parallelization. It demonstrates that the logic programs have an interesting hierarchical class-structure, with respect to pure parallelization.