ifier">f2</span> <span class="special">=</span> <span class="special">[](</span><span class="keyword">const</span> <span class="identifier">cpp_bin_float_quad</span><span class="special">&amp;</span> <span class="identifier">t</span><span class="special">)</span> <span class="special">{</span> <span class="keyword">return</span> <span class="identifier">t</span> <span class="special">*</span> <span class="identifier">t</span> <span class="special">*</span> <span class="identifier">atan</span><span class="sp