In mathematics, a set function is a function whose input is a set. The output is usually a number. Often the input is a set of real numbers, a set of points in Euclidean space, or a set of points in some measure space.
[
"Discrete mathematics",
"Mathematical optimization",
"Topology",
"Mathematical analysis",
"Set (abstract data type)",
"Ring of sets",
"K-approximation of k-hitting set"
]