John L. Bell
University of Western Ontario

"Choice Principles in Intuitionistic Set Theory"

Abstract:
In intuitionistic set theory, the law of excluded middle is known to be derivable from the standard version of the axiom of choice that every family of nonempty sets has a choice function. In this paper it is shown that each of a number of intuitionistically invalid logical principles, including the law of excluded middle, is, in intuitionistic set theory, equivalent to a suitably weakened version of the axiom of choice. Thus these logical principles may be viewed as choice principles.

Back to Talks Page