aggregator_page_categories in drupal-7.x/modules/aggregator/aggregator.pages.inc

Page callback: Displays all the categories used by the Aggregator module.

aggregator_page_sources in drupal-7.x/modules/aggregator/aggregator.pages.inc

Page callback: Displays all the feeds used by the aggregator.

theme_aggregator_categorize_items in drupal-7.x/modules/aggregator/aggregator.pages.inc

Returns HTML for the aggregator page list form for assigning categories.

_aggregator_page_list in drupal-7.x/modules/aggregator/aggregator.pages.inc

Prints an aggregator page listing a number of feed items.

<?php

/**
 * @file
 * Default theme implementation to wrap aggregator content.
 *
 * Available variables:
 * - $content: All aggregator content.
 * - $page: Pager links rendered through theme_pager().
 *
 * @see template_preprocess()
 * @see template_preprocess_aggregator_wrapper()
 *
 * @ingroup themeable
 */
?>
<div id="aggregator">
  <?php print $content; ?>
  <?php print $pager; ?>
</div>