Fuzzy choice functions

The R-greatest and maximal sets of standard choice theory are extended to fuzzy R-greatest and fuzzy maximal sets. Unlike the precise counterparts of these concepts, these two sets do not in general coincide when preferences are reflexive and connected. A stronger than usual version of connectedness under which the two sets are equal is provided. The concept of a fuzzy choice function is introduced and conditions under which a fuzzy choice function may be rationalized as a fuzzy R-greatest or a fuzzy maximal set are discussed. Rationalizability with transitive and weakly transitive fuzzy preference relations is also considered.We are indebted to Professor P. K. Pattanaik for his comments on an earlier version of this paper. We also wish to acknowledge comments made by an anonymous referee from which this paper has benefited greatly. The usual caveat about errors applies.