[GHC] #13790: GHC doesn't reduce type family in kind signature unless its arm is twisted

[GHC]

#13790: GHC doesn't reduce type family in kind signature unless its arm is twisted
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        Reporter:  RyanGlScott       |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler (Type    |              Version:  8.2.1-rc2
  checker)                           |             Keywords:  TypeInType,
      Resolution:                    |  TypeFamilies
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  GHC rejects       |  Unknown/Multiple
  valid program                      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by goldfire):

 Could this be a concrete example that tickles the problems discussed in
 #12088? Perhaps. Either that, or the fix for #11348 didn't go far enough.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13790#comment:1>
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