Php Logic statement synatx error due to comma

Can anyone help

<?php 
if(((count( $replies ) > 6) and 
(count( $replies ) <= 12)) and 
($replyNumber == '3','4','5'))
{ ?>
<execute code......>
<?php } ?>

Why due to use of comma (in replynumber as 3,4,5 is getting an error in code