On Fri, Jan 13, 2017 at 12:55 AM, Cody Goodman <codygman.consulting@gmail.com> wrote:

What exactly does (as ++ bs) ~ (bs ++ as) mean?

It tells the typechecker that the parameters to type-level (++) can be swapped and still produce the same result type (that is, type-level (++) is commutative).

brandon s allbery kf8nh sine nomine associates

allbery.b@gmail.com ballbery@sinenomine.net

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