[GHC] #13097: Num a => Num (Down a)

[GHC]

#13097: Num a => Num (Down a)
-------------------------------------+-------------------------------------
           Reporter:  Iceland_jack   |             Owner:
               Type:  feature        |            Status:  new
  request                            |
           Priority:  normal         |         Milestone:
          Component:                 |           Version:  8.0.1
  libraries/base                     |
           Keywords:                 |  Operating System:  Unknown/Multiple
       Architecture:                 |   Type of failure:  None/Unknown
  Unknown/Multiple                   |
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
-------------------------------------+-------------------------------------
 Let's us write

 {{{#!hs
 >>> deriving instance Num a => Num (Down a)

 >>> (<) 10 20
 True

 >>> (<) @(Down _) 10 20
 False
 }}}

 With #12363


 {{{#!hs
 >>> 10 < @(Down _) 20
 False
 }}}

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13097>
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