Lambda the Ultimate

Sigfpe

...sometimes you can write useful Haskell code merely by writing something that type checks successfully. Often there's only one way to write the code to have the correct type. Going one step further: the Curry-Howard isomorphism says that logical propositions corresponds to types. So here's a way to write code: pick a theorem, find the corresponding type, and find a function of that type.

Learning category theory and formal logic by writing proofs in Haskell.

Cool. :-D