er 1, copy it into register 2 (using register 3), and then move register 2 back to register 1.  So assuming that registers 2 and 3 were empty to begin with, running <span class="math notranslate nohighlight">\(q\)</span> with <span class="math notranslate nohighlight">\(x\)</span> in register <span class="math notranslate nohighlight">\(1\)</span> would give us <span class="math notranslate nohighlight">\(x + x\)</span> in register 1 at the end.</p>
<div class="exercise admonition" id="pre-diag">

<p class=