e </span><span class="obeylines-h"><span class="verb"><span 
class="cmtt-12">bld</span></span></span><span 
class="cmr-12">.</span>
     </li>
     <li 
  class="enumerate" id="x17-16012x5"><span 
class="cmti-12">Apply the preconditioner at each iteration of a Krylov solver. </span><span 
class="cmr-12">This is performed by</span>
     <span 
class="cmr-12">the method </span><span class="obeylines-h"><span class="verb"><span 
class="cmtt-12">apply</span></span></span><span 
class="cmr-12">. When using the P