package objsets

trait Expr
case class Number(n:Int) extends Expr
case class Sum(e1:Expr,e2:Expr) extends Expr

object week4 {
  println("Welcome to the Scala worksheet")

  def show(e: Expr): String = e match {
    case Number(n) => n.toString
    //case Sum(e1,e2) => "( " + show(e1) + " + " + show(e2) + " )"
  }

  "banana"
  Number(1)
}