lub-from-hell-2.scala:3: error: type arguments [Any,Iterable[Any] with Int => Any with scala.collection.generic.Subtractable[Any,Iterable[Any] with Int => Any with scala.collection.generic.Subtractable[Any,Iterable[Any] with Int => Any]{def seq: Iterable[Any] with Int => Any}]{def seq: Iterable[Any] with Int => Any{def seq: Iterable[Any] with Int => Any}}] do not conform to trait Subtractable's type parameter bounds [A,+Repr <: scala.collection.generic.Subtractable[A,Repr]] def foo(a: Boolean, b: collection.mutable.Set[Any], c: collection.mutable.ListBuffer[Any]) = if (a) b else c ^ lub-from-hell-2.scala:4: error: type arguments [Any,scala.collection.mutable.Iterable[Any] with scala.collection.mutable.Cloneable[scala.collection.mutable.Iterable[Any] with scala.collection.mutable.Cloneable[scala.collection.mutable.Iterable[Any] with Cloneable with Int => Any] with Int => Any{def seq: scala.collection.mutable.Iterable[Any] with Cloneable with Int => Any}] with scala.collection.generic.Growable[Any] with Int => Any with scala.collection.generic.Shrinkable[Any] with scala.collection.generic.Subtractable[Any,Iterable[Any] with Int => Any with scala.collection.generic.Subtractable[Any,Iterable[Any] with Int => Any]{def seq: Iterable[Any] with Int => Any}] with scala.collection.script.Scriptable[Any]] do not conform to trait Subtractable's type parameter bounds [A,+Repr <: scala.collection.generic.Subtractable[A,Repr]] def bar(a: Boolean, b: scala.collection.mutable.SetLike[Any,scala.collection.mutable.Set[Any]], c: scala.collection.mutable.Buffer[Any]) = if (a) b else c ^ two errors found