Comment by maweki

I think core of the problem in property-based testing that the property/specification needs to be quite simple compared to the implementation.

I did some property-based testing in Haskell and in some cases the implementation was the specification verbatum. So what properties should I test? It was clearer where my function should be symmetric in the arguments or that there is a neutral element, etc..

If the property is basically your specification which (as the language is very expressive) is your implementation then you're just going in circles.