## Weakened Negative Introspection in Autoepistemic Reasoning (1993)

Venue: | IN PROCEEDINGS OF THE 3RD KURT G#DEL COLLOQUIUM ON COMPUTATIONAL LOGIC AND PROOF THEORY |

Citations: | 4 - 3 self |

### BibTeX

@INPROCEEDINGS{Janhunen93weakenednegative,

author = {Tomi Janhunen},

title = {Weakened Negative Introspection in Autoepistemic Reasoning},

booktitle = {IN PROCEEDINGS OF THE 3RD KURT G#DEL COLLOQUIUM ON COMPUTATIONAL LOGIC AND PROOF THEORY},

year = {1993},

pages = {21122--2},

publisher = {Springer-Verlag}

}

### OpenURL

### Abstract

A new weakened scheme for negative introspection in autoepistemic reasoning is proposed. The scheme is formulated proof-theoretically in terms of enumerations of formulae. The resulting sets of conclusions based on this negative introspection principle, cautious autoepistemic expansions, generalize Moore style stable expansions such that every set of premises has a cautious expansion. A finitary characterization is developed for cautious expansions. The elimination of weakly grounded cautious expansions yields a subclass of cautious expansions: the N-grounded cautious expansions. The least N-grounded cautious expansion is shown to be unique and the intersection of all N-grounded cautious expansions. This is in contrast with Moore style stable expansions. The least N-grounded cautious expansion can be constructed iteratively as the least fixed point of a monotonic operator. Such a construction is exceptional, since autoepistemic expansions are nonconstructive in general. It is also s...