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Mon Jul 16 14:11:21 EDT 2018

Rank N types

I think it had already clicked for me as I recently needed multiple
instantiations of the same function type in setting that made perfect
practical sense, but here is some more explanation:

https://stackoverflow.com/questions/12031878/what-is-the-purpose-of-rank2types

   ... while you can write a function that takes different types of
   arguments without this extension, you can't write a function that
   uses its argument as different types in the same invocation.

It is about being able to instantiate the type multiple times.

The comment about System F is insightful.



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