pan class="keywordsign">-&gt;</span>&nbsp;bool&nbsp;=&nbsp;<span class="string">"caml_sys_is_directory"</span><br>
&nbsp;&nbsp;<span class="keyword">external</span>&nbsp;remove&nbsp;:&nbsp;string&nbsp;<span class="keywordsign">-&gt;</span>&nbsp;unit&nbsp;=&nbsp;<span class="string">"caml_sys_remove"</span><br>
&nbsp;&nbsp;<span class="keyword">external</span>&nbsp;rename&nbsp;:&nbsp;string&nbsp;<span class="keywordsign">-&gt;</span>&nbsp;string&nbsp;<span class="keywordsign">-&gt;</span>&nbsp;unit&nbsp;=&nb