Optimality Theory through Default Logic

Optimality Theory is an approach to linguistic problems which is based on rules with exceptions, resorting to a ranking among rules to resolve conflicts arising from competing rules. In such a way, dealing with linguistic problems amounts to applying rules with exceptions: That is reasoning. A related issue is then about a formalization of the logic at work. An immediate candidate is Default Logic which is dedicated to reasoning from rules with exceptions. Moreover, there are versions of default logic with priorities. We show that Default Logic is well-suited as a specification language capturing Optimality Theory and suggests that implementations of default logic can be applied to run experiments with grammatical interaction in the sense of Optimality Theory and beyond.