Defeasible logic is a non-monotonic logic proposed by Donald Nute to formalize defeasible reasoning. In defeasible logic, there are three different types of propositions:
- strict rules
- specify that a fact is always a consequence of another;
- defeasible rules
- specify that a fact is typically a consequence of another;
- undercutting defeaters
- specify exceptions to defeasible rules.
A priority ordering over the defeasible rules and the defeaters can be given. During the process of deduction, the strict rules are always applied, while a defeasible rule can be applied only if no defeater of a higher priority specifies that it should not.
Famous quotes containing the word logic:
“The much vaunted male logic isn’t logical, because they display prejudices—against half the human race—that are considered prejudices according to any dictionary definition.”
—Eva Figes (b. 1932)