[Haskell] Announce: revamped free theorems generator

[Jean-Philippe Bernardy]

On Sun, Jun 20, 2010 at 12:47 PM, Janis Voigtländer
<jv at informatik.uni-bonn.de> wrote:
> Sebastian Fischer schrieb:
>>
>> Hello,
>>
>> I tried to use the free theorem generator in order to check whether the
>> only values of type `(Bool -> a) -> a` are `($True)` and `($False)`.
>
> Did you manage to do this now?
>
> Driven by Andreas' comment about what he considers "free theorems",
> statements like the above about an exhaustive enumeration of possible
> values of a given type, like
>
> - ($True) and ($False) for type (Bool -> a) -> a
> - id for type a -> a
>
> In any case, for additional possibilities like "exhaustive value
> enumeration (where possible at all)", I don't yet have a generic
> strategy.

Using the main result of our ESOP paper (Testing Polymorphic Properties),
you can get there for a large class of input types.

http://publications.lib.chalmers.se/cpl/record/index.xsql?pubid=99387

Cheers,
JP.