posts_nav_link and excluded articles

Hello, guys / girls?

I’m hidding some articles from view in LOOP via following code:
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<?php if (have_posts()): ?>
<?php while (have_posts()) : the_post(); ?>
<? if(!in_category(500)): ?> //show article

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but post_nav_link() function counts all posts so there is a problem, when I have 11 posts in database and 10 per page setting, I see link to “older articles” but 11th article is not visible of course so page no. 2 is empty.
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