my_tag_text_callback used in theme with is_user_logged_in

<?php get_header(); ?>

<?php
    function my_tag_text_callback( $count ) {
        return sprintf( _n('%s Market', '%s Markets', $count), number_format_i18n( $count ) );
    }
?>

<?php if (is_user_logged_in()): ?>

    MY CONTENT

<?php else : ?>
    <?php wp_login_form(); ?>
<?php endif; ?>

<?php get_footer(); ?>