[GHC] #4295: Review impredicative types

[GHC]

#4295: Review impredicative types
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    Reporter:  simonpj           |        Owner:              
        Type:  bug               |       Status:  new         
    Priority:  normal            |    Milestone:              
   Component:  Compiler          |      Version:  6.12.3      
    Keywords:                    |     Testcase:              
   Blockedby:                    |   Difficulty:              
          Os:  Unknown/Multiple  |     Blocking:              
Architecture:  Unknown/Multiple  |      Failure:  None/Unknown
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 The ticket is a placeholder to remind me to work through the test cases
 for impredicative and higher rank types in the new typechecker.  For now,
 I'm marking many of them as `expect_broken` on this ticket, although I
 think many of them really should fail.
  * Many tests in `boxy/`
  * tcfail198
  * tcfail174
  * tcfail165
  * tcfail145
  * tcfail104
  * tc211

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/4295>
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