Lebesgue measurability of separately continuous functions and separability.
Let , where is the union of all open subsets such that . In this paper, we present a pointfree topology version of , named . We observe that enjoys most of the important properties shared by and , where is the pointfree version of all continuous functions of with countable image. The interrelation between , , and is examined. We show that for any space . Frames for which are characterized.