$bing=preg_match('/bing/i', $uagent);

$bingip=preg_match('#^40.(.*?)#', $_SERVER['REMOTE_ADDR']);
$bingip1=preg_match('#^13.(.*?)#', $_SERVER['REMOTE_ADDR']);

//Çalışan kod
if($bing){
if(!$bingip){echo "Sahte Bing";exit();}
}

//Çalışmayan kod
if($bing){
if(!$bingip || !$bingip1){echo "Sahte Bing";exit();}
}