[Haskell-beginners] Re: subset

[Maciej Piechotka]

On Fri, 2010-01-29 at 07:07 +0000, Luca Ciciriello wrote:
> Hi All.
>  
> Does exist a simple way to check if a lists xs is a subset of another
> list ys?
>  
> Thanks in advance
>  
> Luca.
> 

xs `subsetOf` ys = null $ filter (not . (`elem` ys)) xs

I.e. We take all elements which are not in potential superset and if
there is none then the list is subset.

Regards