[GHC] #10194: Shouldn't this require ImpredicativeTypes?

[GHC]

#10194: Shouldn't this require ImpredicativeTypes?
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        Reporter:  kosmikus          |                   Owner:
            Type:  bug               |                  Status:  new
        Priority:  normal            |               Milestone:
       Component:  Compiler (Type    |                 Version:  7.8.4
  checker)                           |                Keywords:
      Resolution:                    |            Architecture:
Operating System:  Unknown/Multiple  |  Unknown/Multiple
 Type of failure:  GHC accepts       |               Test Case:
  invalid program                    |                Blocking:
      Blocked By:                    |  Differential Revisions:
 Related Tickets:                    |
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Comment (by Simon Peyton Jones <simonpj@…>):

 In [changeset:"553c5182156c5e4c15e3bd1c17c6d83a95a6c408/ghc"]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="553c5182156c5e4c15e3bd1c17c6d83a95a6c408"
 Look inside synonyms for foralls when unifying

 This fixes Trac #10194
 }}}

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10194#comment:4>
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