Re: [Haskell-cafe] What's the difference?

Paul Johnson wrote:

You can regard an "instance" declaration as an inference rule for the type checker, with "=>" meaning "implies" (though I don't think its the answer to your other question about names).

"implies" might be a bad word, because the direction is backwards: Eq a => Ord a is clearly false if read that "Eq a implies Ord a". It is Ord a that implies Eq a. I just read it as "required for" myself. Dan