sp;<span class="keyword">and</span>&nbsp;letop&nbsp;=&nbsp;{<br>
&nbsp;&nbsp;&nbsp;&nbsp;let_&nbsp;:&nbsp;<span class="constructor">Parsetree</span>.binding_op;<br>
&nbsp;&nbsp;&nbsp;&nbsp;ands&nbsp;:&nbsp;<span class="constructor">Parsetree</span>.binding_op&nbsp;list;<br>
&nbsp;&nbsp;&nbsp;&nbsp;body&nbsp;:&nbsp;<span class="constructor">Parsetree</span>.expression;<br>
&nbsp;&nbsp;}<br>
&nbsp;&nbsp;<span class="keyword">and</span>&nbsp;binding_op&nbsp;=&nbsp;{<br>
&nbsp;&nbsp;&nbsp;&nbsp;pbop_op&nbsp;:&n