// test/Test.scala, derived from my own code
package test;
trait Extension { 
  trait SpanNode
  trait LinkedNode  { 
    trait ParseNode extends SpanNode;
    def ParseNode : SpanNode
  }
  def f(node : LinkedNode) : SpanNode = node.ParseNode
}
object Test extends Extension {
  trait LinkedNode extends super.LinkedNode {
    case class ParseNode extends super.ParseNode;
  }
  class LinkedNode0 extends Test.LinkedNode
  def main(args : Array[String]) : Unit = {
    val n = new LinkedNode0
    n.ParseNode // OK
    f(n)        // throws AME
  }
}