[Haskell-cafe] is proof by testing possible?

[Ketil Malde]

Neil Brown <nccb2 at kent.ac.uk> writes:

>> swap :: (a,b) -> (b,a)

>> We don't need to test it at all, it can only do one thing, swap its
>> arguments. (Assuming it terminates.)

> swap = undefined

> Terminates and does not swap its arguments :-)

I think this counts as non-termination, and that for semantic purposes,
any bottom value -- infinite loops, exceptions, undefined -- is treated
equally.

-k
-- 
If I haven't seen further, it is by standing in the footprints of giants