lass="cmmi-10">T</span> names the type <span 
class="ptmri7t-">but not the constructors or field names</span>. The ability to export a type
         without its constructors allows the construction of abstract datatypes (see Section&#x00A0;<a 
href="#x11-1150005.8">5.8<!--tex4ht:ref: abstract-types --></a>).
         </li>
         <li class="itemize">The form <span 
class="cmmi-10">T</span><span 
class="pcrr7t-">(</span><span 
class="cmmi-10">c</span><sub><span 
class="cmr-7">1</span></sub><span 
class="pc