ljs-keyword">implements</span> <span class="hljs-title">Expr</span> </span>{
    Expr t;
    <span class="hljs-function"><span class="hljs-keyword">public</span> Expr <span class="hljs-title">reduce</span><span class="hljs-params">()</span> </span>{ <span class="hljs-keyword">return</span> <span class="hljs-keyword">this</span>; }
    <span class="hljs-function"><span class="hljs-keyword">public</span> Expr <span class="hljs-title">fullReduce</span><span class="hljs-params">()</span> </span>{ <span class="h