to go from an absolute path to a relative
one, meaning that most functions need to handle relative ones even
when that might not be natural. &nbsp;With this functionality,
preconditions requiring absolute paths would be less onerous.

&nbsp; &nbsp;Precondition: p.is_absolute() &amp;&amp; base.is_absolute()

&nbsp; &nbsp;Effects: Extracts a path, rp, from p relative to base such that
canonical(p) == complete(rp, base). &nbsp;Any &quot;..&quot; path elements in rp form
a prefix.

&nbsp; &nbsp;Returns: The ext