 class="o">=</span> <span class="n">cross</span><span class="p">(</span><span class="n">b1</span><span class="p">,</span><span class="n">b2</span><span class="p">)</span>
    <span class="n">b3</span> <span class="o">=</span> <span class="n">b3</span><span class="o">/</span><span class="nb">SQRT</span><span class="p">(</span><span class="nb">DOT_PRODUCT</span><span class="p">(</span><span class="n">b3</span><span class="p">,</span><span class="n">b3</span><span class="p">))</span>
  <span class="k">end subr