Here is a3_2...

| ?- print_profile.
       insns   try/retry      called        name
----------------------------------------------------------------
                             *622410/638372     user:gen_number/3
                              *15962/638372     user:puzzle/4
     5697446     1276740     *638372        user:gen_number/3
                             *622410/638372     user:gen_number/3
----------------------------------------------------------------
                              628833/628833     user:puzzle/4
     3531497           0      628833        user:int_div/3
----------------------------------------------------------------
     2740919           0           1        user:puzzle/4
                              *15962/638372     user:gen_number/3
                              628833/628833     user:int_div/3
----------------------------------------------------------------


Here is a3_2...

| ?- print_profile.
       insns   try/retry      called        name
----------------------------------------------------------------
                              *15560/15961      user:gen_number/3
                                *401/15961      user:puzzle/4
      142434       31919      *15961        user:gen_number/3
                              *15560/15961      user:gen_number/3
----------------------------------------------------------------
                               15723/15723      user:puzzle/4
       88307           0       15723        user:int_div/3
----------------------------------------------------------------
       68546           0           1        user:puzzle/4
                                *401/15961      user:gen_number/3
                               15723/15723      user:int_div/3
----------------------------------------------------------------