worksheet of quotient.

quotient.scala

object quotient {
  def mkCoset[E](objs: Seq[E], equivalence: (E) => E):Iterable[Seq[E]] = {
  	objs.groupBy(e => equivalence(e)).map(p => p._2)
  }                                               //> mkCoset: [E](objs: Seq[E], equivalence: E => E)Iterable[Seq[E]]
 	val coset = mkCoset((1 to 5), (e:Int) => e % 3)
                                                  //> coset  : Iterable[Seq[Int]] = List(Vector(2, 5), Vector(1, 4), Vector(3))
  val originalSet = coset.flatten                 //> originalSet  : Iterable[Int] = List(2, 5, 1, 4, 3)
}