[GHC] #9725: Constraint deduction failure

[GHC]

#9725: Constraint deduction failure
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        Reporter:  heisenbug         |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler (Type    |              Version:  7.8.3
  checker)                           |
      Resolution:                    |             Keywords:
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 simonpj):

 The comment stream suggests that it should work when we get kind
 equalities, which we now have.  So yes, let's add a test and declare
 victory!

 Make sure Lint is happy.

 Simon

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9725#comment:18>
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