Default Reasoning Using Monotonic Logic: Nutter's modest proposal revisited, revised, and implemented.
Karen Ehrlich · MAICS · 2004
It is sometimes necessary to reason non-monotonically, to withdraw previously held beliefs. Default rules and defeasible reasoning have been frequently used to handle such situations. Some years ago, J. Terry Nutter proposed a form of defeasible reasoning involving additional truthvalues that would avoid non-monotonicity in many situations. We adopt and implement much of Nutter’s underlying concept, but use a structure of case frames in our knowledge representation to avoid the need for more than the standard truth values. Our implementation captures most of the advantages of the original proposal and in some cases allows more flexibility.