variances.scala:4: error: covariant type A occurs in contravariant position in type test.Vector[A] of value x
  def append(x: Vector[A]): Vector[A] 
             ^
variances.scala:14: error: covariant type A occurs in contravariant position in type A of value a
    private[this] def setA(a : A) = this.a = a 
                           ^
variances.scala:16: error: covariant type A occurs in invariant position in supertype test.C[A] with ScalaObject of object Baz
    object Baz extends C[A]
           ^
variances.scala:63: error: covariant type A occurs in contravariant position in type => test.Covariant.T[A]{def m: (A) => A} of value x
    val x: T[A] {
        ^
four errors found