Location of functions

Hello,
The code below is from my theme redtimes header file. I checked all the function files there are but could nt see where are the fucntions such as the_title_limited or the_content_limit or the_permalink
where can I find them?

<div id="board">
	<div id="board_post">
		<h3>Featured Post</h3>
		<?php $recent = new WP_Query("showposts=1&orderby=rand"); while($recent->have_posts()) : $recent->the_post();?>
		<h2><?php the_title_limited(70); ?></h2>
		<p><?php the_content_limit(300); ?></p>
		<p><a href="<?php the_permalink() ?>">Read More</a></p>
		<?php endwhile; ?>
	</div>