$p += cs_req    => qw(basic_cs math_req);
$p += basic_cs  => qw(intro_rec comp_org adv_prog);
$p += intro_req => 'intro_cs';
$p += intro_req => qw(introI introII);

##</code><code>##

 
$p += cs_req    =>  basic_cs math_req;
$p += basic_cs  => intro_rec comp_org adv_prog;
$p += intro_req => intro_cs;
$p += intro_req => introI introII;

##</code><code>##

$p->assert(cs_req => qw(basic_cs math_req));