Existential types?

If you're not tied to using an existential type, this should work.

You've lost the types of Seq_ by this point, so the only possible B you can get is SeqAny... As such, you can ascribe be to SeqAny safely (b : SeqAny) ++ b2.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.