[Haskell-cafe] A practical Haskell puzzle

[Yitzchak Gale]

Eric Mertens wrote:
> (but I've had my head in Agda lately)

Indeed, coming across this problem tempted me
to abandon the real world and take refuge in Agda.

> http://hpaste.org/44469/software_stack_puzzle

Wow, so simple, and no higher-rank types! This is the
best solution yet. I am now truly in awe of the power
of GADTs.

Thanks,
Yitz