abstract class A {
  type t;
  abstract class P {
    def f(x: t): unit;
  }
}

abstract class A1 extends A {
  def mkP: A1.this.P;
  val in: t;
}

class B extends A {
  type t = int;
  class P1 extends B.this.P {
    def f(x: int): unit = System.out.println(x + 1);
  }
  def mkP = new P1;
  val in = 3;
}

object test with Executable {
  val a: A1 = new A1 with B; 
  a.mkP.f(a.in);
}