28lib._racket%2Fclass..rkt%29._is-a~3f%2Fc%29%29" class="RktValLink" data-pltdoc="x">is-a?/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="pad_.html" class="RktValLink" data-pltdoc="x">pad%</a></span><span class="RktPn">)</span></td></tr></table></blockquote></div><div class="SIntrapara">Unlinks <span class="RktVar">a-pad</span> from the <span class="RktVar">sinkpad</span>. Returns <span class="RktVal">#t</span> if the pads were unlinked and <span class="RktVal">#f</span> if the 