ss=machine><span class=font-tt>_</span></span> and
<span class=machine><span class=font-tt>s2</span></span><span class=machine><span class=font-tt>_</span></span> respectively, to avoid ambiguity on the <span class=machine><span class=font-tt>x</span></span> label. However, the
label <span class=machine><span class=font-tt>z</span></span> for <span class=machine><span class=font-tt>s3</span></span> is not prefixed, since it is not used elsewhere.<p>The prefix added in front of multiply-defined labels is tak