I see the study of Drapeau et al. (2016), The algebra of conditional sets and the concepts of conditional topology and compacness, Journal of Mathematical Analysis and Applications. They bring the new concept of 'conditional set' (Definition 2.1):
A conditional set X of a non-empty set X and a complete Boolean algebra A is a collection of objects x|a for x in X and a in A such that
- if x|a = y|b, then a = b;
- if x,y in X and a,b in A with a