Re: [Haskell-cafe] Clarification on proof section of HS: The Craft of FP

On Wednesday 04 May 2005 01:32, Ben Rudiak-Gould wrote:

This doesn't work in Haskell because Haskell types aren't constructed in this way. It's harder to prove properties of types in Haskell (and fewer properties actually hold).

Could you explain why this is so? Or rather, what the appropriate technique is in Haskell? I assume it has to do with laziness but I have no idea how it enters the picture. Ben