In this chapter, the three facets of the integration of relational languages and LL are described:
In section 4.1, the loose coupling of REL and LL is described, where the emphasis is on the accessibility of LL functions from predicates (since the other direction is not part of our prototypical implementation).
In section 4.2, the detection and transformation of deterministic predicates is portrayed. For this, first a theoretical foundation of determinism in relational languages is developed (using SLD resolution trees), and then algorithms for the detection and transformation of deterministic predicates, using several intermediate representation languages, are given.
In section 4.3, the implementation of extra-logicals in relational languages via LL functions is described by giving a simple example (global variables and, building upon them, bagof).