1. Property testing framework inspired by quickcheck
2. Difference between unit testing vs property tests
3. Fundamental testing unit is a property. Property consists of input domain, computation, assertion
4. TDD

import org.scalacheck.Prop.forAll

 val prop1 = forAll { x: Int => println(x); x == x}
 prop1.check


def sort(xs: List[Int]) = xs.sorted
forAll {xs: List[Int] =>
    val xs_ = sort(xs)
    val containsAll = (xs.toSet -- xs_.toSet).isEmpty
    if(xs.size == 1) containsAll
    else containsAll && xs_.sliding(2).forall(x => x(0) < x(1))
}