# this gives $result as 1, not 33.  Makes sense, 
# since $val == 4 evaluates to 1.  But, I want $result to 
# be assigned 33, based on the fact that $val == 4. 
$result = ($major_length == 4800) ? 18 
        : ($major_length ==  8552) 
            ? ($val == 4) : 33;

##</code><code>##

    if ($major_length == 4800) {
        $result = 18;
    } elsif ($major_length == 8552) {
        if ($val == 4) {
            $result = 33;
        } else {
            # $result is Unspecified (see A below)
        }
    } else {
        # $result is Unspecified (see B below)
    }

##</code><code>##

$result = ($major_length == 4800)? 18:
          (($major_length == 8552)?
           (($val == 4)? 33:
                        undef):        # see A above
                        undef);        # see B above