[Haskell] Typing in haskell and mathematics

[Lennart Augustsson]

Cale Gibbard wrote:
> Another common thing which is done whenever convenient is to treat
> Cartesian product as associative, and naturally identify the spaces (A
> x A) x A and A x (A x A), along with perhaps A^3 which might be
> functions f: {0,1,2} -> A, 
It's fine to identify (A x A) x A with A x (A x A) in set theory where
they are isomorphic.  But in a language like Haskell this is simply not
true.  Bottom wreaks havoc with many things. :(

	-- Lennart