Conditional Preference Orders and their Numerical Representations

This work provides an axiomatic framework to the concept of conditional preference orders based on conditional sets. Conditional numerical representations of such preference orders are introduced and a conditional version of the theorems of Debreu about the existence of such numerical representations is given. The continuous representations follow from a conditional version of Debreu's Gap Lemma the proof of which is free of any measurable selection arguments but is derived from the existence of a conditional axiom of choice. As an example, a conditional version of the classical von Neumann and Morgenstern representation is provided.