1. include, include_once, require and require_once are expressions not functions, parentheses are not necessary.
2. to move up the directory tree, it's better to use the dirname function instead of relying on /...

Changes proposed in this pull request:

• See above

How to test the feature manually:

1. nothing has changed, everything is working as before

Pull request checklist:

• clear commit messages
• code manually tested
• unit tests written (optional if too hard)
• documentation updated

Additional information can be found in the documentation.