Rough Sets: Let (S, rho) be an approximation space and let U be a subset of S. The rho-upper approximation is ________

the set obtained by taking the union of rho-equivalence classes that have non-empty intersection with set U.

uap sub rho (U) = Union { [x] sub rho that is element of S/P | [x] sub rho intersect U not equal null set }

all sets that contain any members that have membership in [x] sub rho