Tutorial: APPPATH has trailing slash causing 404 error in static page example

I consider myself hardly more than a rank amateur with php and codeigniter ...

I've installed Codeigniter 3.0.0 on a raspberry Pi running Slackware.

I moved the 'application' and 'system' directories above the 'htdocs' folder and made the changes to the index.php file to accommodate the relocation. That all worked (!) so I started on the tutorial with gusto ... and got as far as the "static pages".

I quickly hit a "404 not found" error.

I have traced it to the line in the Pages.php controller view method. The tutorial says to insert this code ...

public function view($page = 'home')
{
if ( ! file_exists(APPPATH.'/views/pages/'.$page.'.php'))
{
// Whoops, we don't have a page for that!
show_404();
}

From inserting a print_r(APPPATH) I see my APPPATH has a TRAILING SLASH /var/www/application/ which causes the above code to have two slashes between 'application' and 'views/pages' and that causes file_exists to return false ...

Is this just a typo in the tutorial, or is there some codeigniter - or php - configuration parameter that appends a trailing slash to paths ?