:- checked calls qsort(A,B)
   : ( list(num,A) ).

:- check success qsort(A,B)
   => sorted_num_list(B).

:- checked calls partition(A,B,C,D)
   : ( ground(A), ground(B) ).

:- checked success partition(A,B,C,D)
   => ( list(num,C), ground(D) ).

:- checked comp partition(_A,_B,_C,_D)
   + not_fails.

:- checked comp partition(_A,_B,_C,_D)
   + det.

:- checked comp partition(A,B,C,D)
   + terminates.

:- check calls append(A,B,C)
   : list(num,B).
