 /// Defines equality for sets of equatable elements.
 public func == <Element: Hashable> (a: Set<Element>, b: Set<Element>) -> Bool {
 	return a.values == b.values
-}
-
-
-/// Set is reducible.
-extension Set {
-	/// Combines each element of the receiver with an accumulator value using `combine`, starting with `initial`.
-	public func reduce<Into>(initial: Into, combine: (Into, Element) -> Into) -> Into {
-		return Swift.reduce(self, initial, combine)
-	}
 }
 
 

	/// Returns a new set with all elements from the receiver which are not contained in `set`.
	public func difference(set: Set) -> Set {
		return Set(filter(self) { !set.contains($0) })
	}



}


/// Extends a `set` with the elements of a `sequence`.
public func += <S: SequenceType> (inout set: Set<S.Generator.Element>, sequence: S) {
	set.extend(sequence)
