On the difference between the cardinalities of measurable value functions and von Neumann-Morgenstern utility functions

Dyer and Sarin (1979) proposed an important generalization of the additive-multiplicative decomposition theorem for von Neumann-Morgenstern (vNM) utility functions to measurable value functions based on the cardinality property of measurable value functions. However, because of a difference between the cardinality of measurable value functions and the cardinality of vNM utility functions, an additional technical condition is needed, and presented here, for the decomposition theorem to hold.