[GHC] #2256: Incompleteness of type inference: must quantify over implication constraints

[GHC]

#2256: Incompleteness of type inference: must quantify over implication
constraints
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        Reporter:  simonpj           |                Owner:  simonpj
            Type:  bug               |               Status:  new
        Priority:  lowest            |            Milestone:
       Component:  Compiler (Type    |              Version:  6.8.2
  checker)                           |             Keywords:
      Resolution:                    |  QuantifiedConstraints
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 RyanGlScott):

 Simon, it's unclear what we should do with this ticket now that
 `QuantifiedConstraints` are in GHC. Was the intention here to actually
 change GHC to infer quantified constraints in certain places? My hunch is
 "no", especially in light of comment:16. If so, can we simply close this
 ticket?

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/2256#comment:30>
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