\begin{verbatim}

 smodels version 2.25. Reading...done
 Answer: 1
 Stable Model:

 occurs(unstack(a,b),1)
 occurs(put_down(a),2)
 occurs(pick_up(c),3)
 occurs(stack(c,b),4)
 occurs(pick_up(a),5)
 occurs(stack(a,c),6)

 True
 Duration: 1.035
 Number of choice points: 0
 Number of wrong choices: 0
 Number of atoms: 2612
 Number of rules: 29460
 Number of picked atoms: 177
 Number of forced atoms: 30
 Number of truth assignments: 10872
 Size of searchspace (removed): 0 (0)

\end{verbatim}