The Manchester twins : conflicts between directed obligations

Term-modal logic uses modal operators that are indexed with terms of the language,which allows for quantification over these operators. Term-modal deontic logics (TMDL) can capture reasoning with rules, directed, and undirected obligations. Us-ing the rich language of TMDL, we identify different types of deontic conflicts between directed obligations and describe reasoning in the face of these conflicts. We develop several monotonic logics in the TMDL family and show that none is capable of cap-turing all plausible deontic principles, while also being conflict-tolerant. To remedythis we develop several non-monotonic extensions in the format of adaptive logics.We end by isolating one of these,TMDLm, and commenting on it.Term-modal logic uses modal operators that are indexed with terms of the language,which allows for quantification over these operators. Term-modal deontic logics (TMDL) can capture reasoning with rules, directed, and undirected obligations. Us-ing the rich language of TMDL, we identify different types of deontic conflicts between directed obligations and describe reasoning in the face of these conflicts. We develop several monotonic logics in the TMDL family and show that none is capable of cap-turing all plausible deontic principles, while also being conflict-tolerant. To remedythis we develop several non-monotonic extensions in the format of adaptive logics.We end by isolating one of these,TMDLm, and commenting on it.C