abstract-concrete-methods.scala:7: error: class Outer2 needs to be abstract, since method score in trait Outer of type (i: Outer2#Inner)Double is not defined
(Note that This#Inner does not match Outer2#Inner: class Inner in class Outer2 is a subclass of trait Inner in trait Outer, but method parameter types must match exactly.)
class Outer2 extends Outer[Outer2] {
      ^
one error found
