$post['isfirstshown'] doesn't exist? Alternative?

[TheMilkCarton]

I'm trying to loop things on every page of a thread, but for whatever reason vBulletin hasn't included "$post['isfirstshown']"?? $post['islastshown'] works just fine, so what's the deal?

Anyway, just thought I'd ask what would be the easiest way to emulate "isfirstshown"? Whether it be a plugin that calculates every multiple of the "Posts per page" # + 1 (i.e. 1, 16, 31, 46, 61...) and inserts the code into postcounts that equal those numbers, or actually modifying the vBulletin code to create a real "isfirstshown".

I guess it would help if I were at my PC.. then I could just search through to see how they've done the "islastshown" code.
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Edit: Sigh.. I already found my answer:

<if condition="$post[postcount] % $vboptions[maxposts] == 1">

I found this by accident while looking up something else (GO FIGURE). I would just delete this whole post, but I at least wanted other people to know how to do it. Although I guess I'm the only one who didn't know this.