[GHC] #15453: Bug in opt_trans_rule in OptCoercion

[GHC]

#15453: Bug in opt_trans_rule in OptCoercion
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        Reporter:  ningning          |                Owner:  ningning
            Type:  bug               |               Status:  merge
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.4.3
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D5018
       Wiki Page:                    |
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Comment (by simonpj):

 Great work!

 We have a paper about `OptCoercion`, [https://www.microsoft.com/en-
 us/research/publication/evidence-normalization-system-fc-2/ Evidence
 normalisation in System FC]. It is a million times more comprehensible
 than `OptCoercion.hs` itself.

 If I found the sources, would anyone (Ryan?) be willing to
  * put (a version of) it in the GHC repo
  * update it to be correct, and to cover `GRefl`

 Thanks

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15453#comment:9>
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