The exact unification type of an equational theory is based on a new preorder on substitutions, called the exactness preorder, which is tailored towards transferring decidability results for unification to disunification. We show that two important results regarding the unification type of commutative theories hold not only for the usual instantiation preorder, but also for the exactness preord...

The Unification Tutor is experimental Intelligent Tutoring System for the domain of the unification of Prolog terms. It demonstrates the interactive use of Feature-Based Modelling an approach to cognitive modelling that has been presented at previous ASCILITE Conferences (Webb, 1988b.) The Unification Tutor has been used by Third Year Computer Science students at La Trobe University during Sept...

Motivated in part by recent demonstrations that electroweak gauge coupling unification may occur at a low scale, we analyze the requirements on the Higgs mass if the gauge coupling unification is to be perturbative. We consider an infinite set of possible unification scenarios parametrized by the value of sin θW at the unification scale Λ, and show the Higgs boson mass limits based on the minim...

Second-Order Unification is undecidable even for very specialized fragments. The signature plays a crucial role in these fragments. If all symbols are monadic, then the problem is NP-complete, whereas it is enough to have just one binary constant to lose decidability. In this work we reduce Second-Order Unification to Second-Order Unification with a signature that contains just one binary funct...

We show that the conventional first-order algorithm of unification can be simulated by finite artificial neural networks with one layer of neurons. In these unification neural networks, the unification algorithm is performed by error-correction learning. Each time-step of adaptation of the network corresponds to a single iteration of the unification algorithm. We present this result together wi...

This paper presents a parsing algorithm in Prolog using GULP, based on dependency grammar and unification-based grammar.1 It parses declarative sentences of a free-word-order language, Korean. The dependency grammar accepts free order of the words in a sentence. Unification-based features separate the grammar from the parsing algorithm and also simplify the notation of the grammar. GULP (Graph ...

The unification of simply typed λ-terms modulo the rules of ßand η-conversions is often called "higherorder" unification because of the possible presence of variables of functional type. This kind of unification is undecidable in general and if unifiers exist, most general unifiers may not exist. In this paper, we show that such unification problems can be coded as a query of the logic programm...

The unification of simply typed λ-terms modulo the rules of ßand η-conversions is often called "higherorder" unification because of the possible presence of variables of functional type. This kind of unification is undecidable in general and if unifiers exist, most general unifiers may not exist. In this paper, we show that such unification problems can be coded as a query of the logic programm...

We propose a practical path-based framework for deriving and simplifying source-tracking information for term unification in the empty theory. Such a framework is useful for debugging unification-based systems, including the diagnosis of ill-typed programs and the generation of success and failure proofs in logic programming. The objects of source-tracking are deductions in the logic of unifica...

We propose a path-based framework for deriving and simplifying source-tracking information for first-order term unification in the empty theory. Such a framework is useful for diagnosing unification-based systems, including debugging of type errors in programs and the generation of success and failure proofs in logic programming. The objects of source-tracking are deductions in the logic of ter...