<bicond>

<bicond> (bi-conditional feature-structure constraint) defines a biconditional feature-structure constraint; both consequent and antecedent are specified as feature structures or groups of feature structures; the constraint is satisfied if both subsume a given feature structure, or if both do not. 18.11 Feature System Declaration
Module iso-fs — 18 Feature Structures
Used by
fsConstraints
May contain
iso-fs: f fs iff
Declaration 

<rng:element name="bicond">
 <rng:ref name="att.global.attributes"/>
 <rng:group>
  <rng:choice>
   <rng:ref name="fs"/>
   <rng:ref name="f"/>
  </rng:choice>
  <rng:ref name="iff"/>
  <rng:choice>
   <rng:ref name="fs"/>
   <rng:ref name="f"/>
  </rng:choice>
 </rng:group>
</rng:element>
element bicond { att.global.attributes, ( ( fs | f ), iff, ( fs | f ) ) }
Example
<bicond>
 <fs>
  <f name="FOO">
   <symbol value="42"/>
  </f>
 </fs>
 <iff/>
 <fs>
  <f name="BAR">
   <binary value="true"/>
  </f>
 </fs>
</bicond>