[<<][compsci][>>][..]Fri Oct 28 13:47:56 EDT 2011

Main idea is that multi-param type classes are relations = sets of tuples, and can be seen as relational databases. The basic problem with multi-param type classes is ambiguity. When composing operations, it might be that some type parameters that are in the constraints no longer appear in the right hand side. I.e. TypeRel a b c => a -> b Here 'c' is ambiguous. See [1] section 2.4 for examples. [1] http://www.reddit.com/r/haskell/comments/7oyg5/ask_haskellreddit_can_someone_explain_the_use_of/

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