most programming language designers are not familiar with type theory. SPJ, Odersky, Leroy, Hejlsberg, Syme et al are familiar with type theory, it's not r

most programming language designers are not familiar with type theory. SPJ, Odersky, Leroy, Hejlsberg, Syme et al are familiar with type theory, it's not rocket science. parametric polymorphism There are well-rehearsed reasons for excluding PP. I don't agree with them, but those choices were not made from ignorance. I have not worked in the software industry I invite you to change this, and once you have a few years of industrial programming experience, to reconsider.