Home/ Questions/Q 7573521
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-05-30T16:12:14+00:00

I remember reading somewhere that Hindley Milner was a restriction on system-f. If that

  • 0

I remember reading somewhere that Hindley Milner was a restriction on system-f. If that is the case, could someone please provide me with some terms that can be typed in system-f but not in HM.

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    Anything involving higher-ranked (i.e. “first-class”) polymorphism. For example:

    lambda (f : forall A. A -> A). (f Int 1, f String "hello")

    This function would have the type (forall A. A -> A) -> Int * String, which is not expressible in HM, where all polymorphic type schemes must be in “prenex” form (i.e. the quantifier may only occur on the outside, never nested).

    • 0