a new theoretical model

*"In specifying this improved version of Prolog,
I replaced the notion of unification by the notion of
solving equations in a given domain. This allowed me to
introduce the concept of infinite trees and also of
inequality constraints: the new unification algorithm then became
safe from loops. It also became possible
to check if two objects are unequal without using the search
space cut operation."*

In Prolog, objects are trees — finite or infinite. Indeed, trees deserve a fundamental place in computing. They model data structures as well as processing traces.

In 1984 the PrologIA company was created to commercialise Prolog II.