Output Existentials

I spent over a year trying to improve my proposal how to easyly implement Existential types into the Haskell. And I have a brilliant idea! In Haskel forall quantifier is stands for … input type! So we add exists quantifer for … output type! ForallType during Typecheck is checked and become Monomorhic by substitutional law. But ExistentialType during Typecheck is checked but remains Polymorphic. And … during runtime it could be substituted to Monomorphic type. Output Existentials do NOT cov...