sp;<span class="constructor">Obj</span>.t&nbsp;<span class="keywordsign">-&gt;</span>&nbsp;int&nbsp;<span class="keywordsign">-&gt;</span>&nbsp;unit&nbsp;=&nbsp;<span class="string">"caml_obj_truncate"</span><br>
&nbsp;&nbsp;<span class="keyword">external</span>&nbsp;add_offset&nbsp;:&nbsp;<span class="constructor">Obj</span>.t&nbsp;<span class="keywordsign">-&gt;</span>&nbsp;<span class="constructor">Int32</span>.t&nbsp;<span class="keywordsign">-&gt;</span>&nbsp;<span class="constructor">Obj</span>.t&nbsp