How to combine two <if> conditionals

[viper357]

Hi all. I've googled and tried but I can't anymore, lol.

Can anyone help me how to combine these two conditionals please.

<if condition="in_array($forumid, array(X,Y,Z))">
and
<if condition="$thread['postuserid'] == $post['userid']">

I've tried everything on google and vb.org and vb.com but I just can't get it right.

This code is being placed into the postbit_legacy template and what I want it to do is, if in a certain forum then an image/link will be displayed but only on the original thread starters posts.

If the conditionals are used separately then they work fine, but as soon as I try to use both they seem to cancel each other out somehow. I've tried so many different ways of combing them but I'm not a coder.

Thanks.