[Haskell-cafe] Does GHC recognise that CmpSymbol s1 s2 ~ EQ implies s1 ~ s2 ?

Evgeny Permyakov permeakra at gmail.com
Fri Apr 24 11:07:18 UTC 2020

By semantic
 CmpSymbol s1 s2 ~ EQ should be equivalent to s1 ~ s2 for s1 , s2 :: Symbol

Does GHC recognize it? If not, is there some trick to obtain evidence of
the second constraint from the first ? I'm talking about context of type
class instance declarations.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.haskell.org/pipermail/haskell-cafe/attachments/20200424/20555c64/attachment.html>

More information about the Haskell-Cafe mailing list