Definition Of Unification Algorithm

The unification algorithm in prolog is roughly this.

Definition of unification algorithm. Otherwise if is a variable then instantiate to. If and are constants i e. It returns fail if the expressions do not match with each other. Firstly 1 we have to allow for the possiblity that val is a variable and indeed is the same variable as var.

Unification is used in automated reasoning technology which. Atoms or numbers then if they are the same succeed. Unification is a key component of all first order inference algorithms. So let us now consider the definition of unify var.

It returns a list representing the composition of the substitutions that were performed during the match. The unification algorithm is no longer minimal and the same solutions may be computed repeatedly. The act or process of. Depending on the framework a complete and minimal substitution set may have at most one at most finitely many or possibly infinitely many members or may not.

An empty list nil indicates that a match was found without any substitutions. The unification algorithm consists of two mutually recursive procedures unify and unify one which try to unify a list of pairs and a single pair respectively. A unification algorithm should compute for a given problem a complete and minimal substitution set that is a set covering all its solutions and containing no redundant members. In this case unification is trivial with the existing frame 1 1.

The unification algorithm is listed below as a procedure unify l1 l2. If is a variable then instantiate to. Df un given two terms and which are to be unified. The act or process of bringing together or combining things or people.

If the list contains a single value f it indicates that the unification procedure failed. The result of the computation is the most general unifier for the list of pairs or the pair respectively. Schmidt 1998 a presents improved unification rules for transitivity where the world paths are unified mainly from left to right thus reducing the branching rate of the unification tree. In other words by replacing certain sub expression variables with other expressions unification tries to identify two symbolic expressions.