l-icons"></i></a></span> <span class="modifier_kind"><span class="modifier"></span> <span class="kind">val</span></span> <span class="symbol"><span class="name">fe</span><span class="result">: <span name="trepplein.Expr" class="extype">Expr</span></span></span></li><li class="indented0 " name="java.lang.Throwable#fillInStackTrace" group="Ungrouped" fullComment="yes" data-isabs="false" visbl="pub"><a id="fillInStackTrace():Throwable"></a> <span class="permalink"><a href="../../provingground/interface/Lean