n></span> <span class="symbol"><span class="implicit">ensuring</span><span class="params">(<span name="cond">cond: <span name="scala.Boolean" class="extype">Boolean</span></span>)</span><span class="result">: <a href="" name="provingground.Context.AppendConstant" id="provingground.Context.AppendConstant" class="extype">AppendConstant</a>[<span name="provingground.Context.AppendConstant.U" class="extype">U</span>]</span></span><div class="fullcomment"><dl class="attributes block"><dt class="implicit">Implici