ckward</span><span class="p">(</span><span class="n">ctx</span><span class="p">,</span> <span class="n">grad_y</span><span class="p">:</span> <span class="n">Tensor</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="n">Tensor</span><span class="p">:</span>
        <span class="n">binary_sign</span><span class="p">,</span> <span class="o">=</span> <span class="n">ctx</span><span class="o">.</span><span class="n">saved_tensors</span>
        <span class="k">return</span> <span class="n">