Doutoramento em Informática
An Abstract Model for Parrallel Execution of Prolong
Pedro José Patinho

 (Regime Especial de Apresentação de Tese em Conformidade com o artº 33º do Decreto-Lei nº 74/2006 de 24 Março, republicado pelo Decreto-Lei nº 115/2013 de 7 de Agosto)

Logic programming has been used in a broad range of fields, from artifficial intelligence applications to general purpose applications, with great success. Through its declarative semantics, by making use of logical conjunctions and disjunctions, logic programming languages present two types of implicit parallelism: and-parallelism and or-parallelism.

This thesis focuses mainly in Prolog as a logic programming language, bringing out an abstract model for parallel execution of Prolog programs, leveraging the Extended Andorra Model  (EAM) proposed by David H.D. Warren, which exploits the implicit parallelism in the programming language. A reference implementation for the proposed model is also presented.

This work also presents a survey on the state of the art relating to implemented Prolog compilers, either sequential or parallel, along with a walk-through of the current parallel programming frameworks. The main used model for Prolog compiler implementation, the Warren Abstract  Machine (WAM) is also analyzed, as well as the WAM’s successor for supporting parallelism, the EAM.

Keywords:  Prolog, Logic Programming, Extended Andorra Model, Parallelism