Predicates in Prolog
There was a simple program that has five clauses. Head is a compound term for each first three clauses with functor parent. It has two arguments with 2 arity.
The following program includes the clauses for which functor parent is contained by the head, but a different arity.
In the same program, we can also use a parent as an atom.
The above example can cause make confusion too.
An atom can appear as a rule head or as a fact. For example,
The above example regards as a predicate with no arguments, i.e., go/0.
In the previous Prolog Clauses file, we have an example of Animals Program 2, which has five predicates: dog/1, cat/1, large/1, small/1, and large_animal/1. Facts are defined by the first 18 clauses, which represent the predicates dog/1, cat/1, large/1, and small/1 in 6, 4, 7
, and 1 clause respectively. The rules are defined by the final two clauses. Both clauses define large_animal/1 predicate.
Declarative Interpretation of Rules
Declarative and procedural interpretation both describes the rules. The following example shows the declarative interpretation of the rules as follows:
In the above example, 'chases(A, B) is true if dog(A) is true, and cat(B) is true, and write(A) is true, etc.'
In the procedural interpretation, "to satisfy chases(A, B), first satisfy dog(A), then satisfy cat(B), then satisfy write(A), etc."
Facts are interpreted declaratively as follows:
The above will be read as 'bengal is a cat'.