Programmazione logica strutturata: analisi di una implementazione prototipale

We discuss the implementation of a logic programming language extended with structuring mechanism, based on the abstract machine developed by D.H.D. Warren  (WAM). The language (called Ctx_Prolog in this work) enables  the definition of disjointed logic theories, which may dinamically combined during the computation.
We have considered and compared two different approaches to implementation: the former is based on translation from structured logic programs to Prolog programs, to be afterwards executed on a standard WAM; the latter is based on direct compilation for S-WAM, our extended WAM.
Notwithstanding a strong correlation between results and applications, all the examples made show that the second approach is consistently more desirable because of its higher efficiency.