Script started on Mon Oct 09 11:26:15 2000

<33 nova:~/web/perl >   cat CrossProd.cgi


print "\n{ ";

for ($i = 1; $i <= 8; $i++)
{
    for ($j = 1; $j <= 8; $j++)
    {
        if ($i == 8 && $j == 8)
        {
           print "($i,$j) ";
        }
        else
        {
           print "($i,$j), "
        }
    }

    if ($i < 8)
    {
        print "\n  ";
    }
    else
    {
        print " }\n\n";
    }
}

<34 nova:~/web/perl >   perl CrossProd.cgi


{ (1,1), (1,2), (1,3), (1,4), (1,5), (1,6), (1,7), (1,8), 
  (2,1), (2,2), (2,3), (2,4), (2,5), (2,6), (2,7), (2,8), 
  (3,1), (3,2), (3,3), (3,4), (3,5), (3,6), (3,7), (3,8), 
  (4,1), (4,2), (4,3), (4,4), (4,5), (4,6), (4,7), (4,8), 
  (5,1), (5,2), (5,3), (5,4), (5,5), (5,6), (5,7), (5,8), 
  (6,1), (6,2), (6,3), (6,4), (6,5), (6,6), (6,7), (6,8), 
  (7,1), (7,2), (7,3), (7,4), (7,5), (7,6), (7,7), (7,8), 
  (8,1), (8,2), (8,3), (8,4), (8,5), (8,6), (8,7), (8,8)  }

<36 nova:~/web/perl >   cat SubSet1.cgi


#  This PERL program demonstrates the Cartesian Products and subsets
#      of A cross A where 
#                         A = { 1, 2, 3, 4, 5, 6, 7, 8 }

#  After the IF statement below is described, you should be able to
#      describe the subset using the example handouts and textbook
#      notation.

print "\n\n{ ";

for ($i = 1; $i <= 8; $i++)
{
    for ($j = 1; $j <= 8; $j++)
    {
        if ($i + $j == 8 || $i * $j == 16 || $i * $j == 32)
        {
           print "($i,$j) ";
        }
    }
}

print "}\n\n";

#  Suppose the above if (  ) statement were modified as follows:

#                 if ($i + $j == 5 || $i * $j == 8 || $i * $j == 64)

#  Enumerate the members of the set that would be printed out.

<37 nova:~/web/perl >   perl SubSet1.cgi



{ (1,7) (2,6) (2,8) (3,5) (4,4) (4,8) (5,3) (6,2) (7,1) (8,2) (8,4) }

<38 nova:~/web/perl >  ^Dexit

script done on Mon Oct 09 11:27:13 2000