t_channel
&nbsp;&nbsp;val&nbsp;descr_of_in_channel&nbsp;:&nbsp;Stdlib.in_channel&nbsp;-&gt;&nbsp;UnixLabels.file_descr
&nbsp;&nbsp;val&nbsp;descr_of_out_channel&nbsp;:&nbsp;Stdlib.out_channel&nbsp;-&gt;&nbsp;UnixLabels.file_descr
&nbsp;&nbsp;type&nbsp;seek_command&nbsp;=&nbsp;Unix.seek_command&nbsp;=&nbsp;SEEK_SET&nbsp;|&nbsp;SEEK_CUR&nbsp;|&nbsp;SEEK_END
&nbsp;&nbsp;val&nbsp;lseek&nbsp;:
&nbsp;&nbsp;&nbsp;&nbsp;UnixLabels.file_descr&nbsp;-&gt;&nbsp;int&nbsp;-&gt;&nbsp;mode:UnixLabels.seek_command&nbsp;-&gt