Saturated set
In mathematics, in particular in topology, a subset of a topological space is saturated if it is an intersection of open subsets of X. In a T1 space every set is saturated.
An alternative definition for saturated sets comes from surjections, these definitions are not equivalent: let be a surjection; a subset C of X is called saturated with respect to p if for every p−1 that intersects C, p−1 is contained in C. This is equivalent to the statement that p−1p=C''.
