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<p class="MsoNormal" style="margin-left:36.0pt">We have to be careful in how we define "equality" in the above sentence, including class constraints that (may) have superclass equality constraints.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Indeed. That’s what happens now.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal" style="margin-left:36.0pt">I do think this would work.<o:p></o:p></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US">Cool. Nick or Iavor: would you like to turn this conversation into a ticket?<o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US">(Although it is technically user-facing, it is a very small corner and I’m not sure it would need a GHC proposal – others may want to comment.)<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="mso-fareast-language:EN-US">Simon<o:p></o:p></span></p>
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<p class="MsoNormal"><b><span lang="EN-US">From:</span></b><span lang="EN-US"> Richard Eisenberg <rae@cs.brynmawr.edu>
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<b>Sent:</b> 21 May 2019 09:43<br>
<b>To:</b> Simon Peyton Jones <simonpj@microsoft.com><br>
<b>Cc:</b> Nicolas Frisby <nicolas.frisby@gmail.com>; Iavor Diatchki <iavor.diatchki@gmail.com>; ghc-devs@haskell.org; Ryan Scott <ryan.gl.scott@gmail.com><br>
<b>Subject:</b> Re: Bug or feature?<o:p></o:p></span></p>
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<p class="MsoNormal">On May 21, 2019, at 10:23 AM, Simon Peyton Jones via ghc-devs <<a href="mailto:ghc-devs@haskell.org">ghc-devs@haskell.org</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal">But (A) looks sound to me. <o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">I like (A). (B) makes me nervous, too.<o:p></o:p></p>
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<p class="MsoNormal">> A. An implication is considered to “bind local equalities” iff it has at least one given equality whose free variables are not all bound by the same implication.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">We have to be careful in how we define "equality" in the above sentence, including class constraints that (may) have superclass equality constraints. I do think this would work.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Richard<o:p></o:p></p>
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