"cartesian classes"

[Hal Daume III]

> A very concrete, but na=EFve, question: what is the syntax for defining
> functional dependencies in Hugs and GHC? Since Mark Jones' syntax was
> abstract in his paper, it is kind of hard to deduce an ASCII equivalence
> (I have tried to figure out how to create a curly arrow from the
> keyboard ;-)

I can't comment on the rest, but for this:


class Foo a b c e | a b -> c, b -> c d where ...


means "a and b together determing c, and b by itself determines c and d"