class Point[T : Numeric](val x:T, val y:T) {
  override def toString = "Numeric(" + x + ", " + y + ")"

  def + (other : Point[T]) : Point[T]  = new Point[T] ( plus(this.x, other.x), plus(this.y, other.y))
  def - (other : Point[T]) : Point[T] = new Point[T] ( minus(this.x, other.x), minus(this.y, other.y))
  def unary_- : Point[T] = new Point[T](negate(this.x), negate(this.y))

  def == (other : Point[T]) : Boolean = (this.x == other.x && this.y == other.y)
  def != (other : Point[T]) : Boolean = !(this == other)

  private val numeric = implicitly[Numeric[T]]

  private def plus(x: T, y: T) =  numeric.plus (x, y)
  private def minus(x: T, y: T) = numeric.minus (x, y)
  private def negate(x: T) = numeric.negate (x)
}