Problem Statement

Rename:

This should be done twice:   once "here", i.e. in the current working directory and once in the filesystem root. It can be assumed that the user has the rights to do so. (In unix-type systems, only the user root would have sufficient permissions in the filesystem root.)

Let's start with the solution:

RENAME "input.txt" TO "output.txt"
RENAME "/input.txt" TO "/output.txt"
RENAME "docs" TO "mydocs"
RENAME "/docs" TO "/mydocs"