RE: [Haskell-cafe] Re: coherence when overlapping?

| I believe that GHC's overlapping instance extensions | effectively uses inequalities. I tried to write down GHC's rules in the manual: http://haskell.org/ghc/dist/current/docs/users_guide/type-extensions.htm l#instance-decls The short summary is: - find candidate instances that match - if there is exactly one, choose it - if the is more than one, choose the best fit UNLESS that choice would be changed if a type variable was instantiated Simon