[GHC] #9072: RankNTypes composition now requires ImpredicativeTypes

[GHC]

#9072: RankNTypes composition now requires ImpredicativeTypes
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        Reporter:  gelisam                    |            Owner:
            Type:  bug                        |           Status:  closed
        Priority:  normal                     |        Milestone:
       Component:  Compiler (Type checker)    |          Version:  7.8.2
      Resolution:  invalid                    |         Keywords:
Operating System:  Unknown/Multiple           |     Architecture:
 Type of failure:  GHC rejects valid program  |  Unknown/Multiple
       Test Case:                             |       Difficulty:  Unknown
        Blocking:                             |       Blocked By:
                                              |  Related Tickets:
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Changes (by simonpj):

 * status:  new => closed
 * resolution:   => invalid


Comment:

 This is, I guess, a bug in 7.6.  You really do need impredicative
 instantiation for the application of `(.)` to work.  So I don't think this
 is a bug in 7.8.  Yell if you disagree.

 Simon

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9072#comment:1>
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