span> <span class="identifier">specified</span> <span class="identifier">it</span> <span class="identifier">is</span> <span class="identifier">an</span> <span class="identifier">MPL</span> <span class="identifier">lambda</span> <span class="identifier">expression</span> <span class="identifier">which</span> <span class="identifier">is</span> <span class="identifier">invoked</span> 
                     <span class="identifier">with</span> <span class="identifier">the</span> <span class="identifier">inner</s