How to use === in scalaz

typesafeEquals.scala

//declare the data structure and the Equal instance
import scalaz._
import Scalaz._

case class MyThing(thing1: String, thing2: String)

object MyThing {
  implicit def MyThingEqual = new Equal[MyThing] {
    override def equal(t1: MyThing, t2: MyThing) = (t1.thing1 === t2.thing1) && (t1.thing2 === t2.thing2)
  }
}

//use it
import scalaz._
import Scalaz._
import MyThing._

val t1 = MyThing("abc", "def")
val t2 = MyThing("abc", "def")
t1 === t2 //should return true