Artificial Intelligence and Soft Computing: Behavioral ... - Arteimi.info

Before presenting the architecture of a production system, applied to
intelligent problem solving, let us first introduce the functionaries of its
modules.
3.2 Production Rules
The structure of a production rule PR1 can be formally stated as follows:
PR1: P1 (X) Λ P2 (Y) Λ .. Pn (X, Z) → Q1 (Y) V Q2 (Z) V .. Qm (Y, X)
where Pi and Qj are predicates; x, y, z are variables; “Λ“, “V” , and “ →”
denote the logical AND, OR and if-then operators respectively. The left-hand
side of a PR is called the antecedent / conditional part and the right-hand side
is called the consequent / conclusion part. Analogously, the left-side symbol
Pi is called the antecedent predicate, while the right-side symbol Q j is called
the consequent predicates.
It should be pointed out that the antecedent and consequent need not be
always predicates. They may equally be represented by object-attribute-value
triplets. For example, (person-age-value) may be one such triplet. To represent
the rules in this fashion, we consider an example, presented in PR2.
PR2 : if (person age above-21) &
(person wife nil) &
(person sex male)
then (person eligible for marriage) .
It should further be noted that though object-attribute-value in PRs are
often represented using variables, still the presence of constants in the tripletform
cannot be excluded. PR3, given below, is one such typical example.
PR3: if (Ram age 25) &
(Ram wife nil) &
(Ram sex male)
then (Ram eligible for marriage).
In the last example person’s name and age are explicit in the PR.
3.3 The Working Memory
The working memory (WM) generally holds data either in the form of clauses
or object-attribute-value (OAV) triplet form. The variables in the antecedent
predicates / OAV relationship of the antecedent part of PRs are matched