This package defines the data structure representing logics, e.g., Atom, Predicate, Term, etc. Also, it bridges these objects to relational tables in DBMS.
Following figure illustrates the relationship between classes in this package, and the relationship between class and database table. For example, from this figure, we can see that, an Atom object is formed by a Tuple object and a Predicate object. And a Predicate object is associated with two database tables.
There are four kinds of database tables. type_TypeName table saves the constant ID of type TypeName. pred_PredicateName table saves grounded instances of predicate PredicateName. act_pred_PredicateName table saves the active atoms of predicate PredicateName. ClauseName_instances table saves instances of clause ClauseName. Here by instance, it means the possible binding from meta-variable to constant. By such bindings, you can get clauses as the same as your input program.