an class="fu">transf.abt</span><span class="op">(</span><span class="va">xi</span><span class="op">)</span></span>
<span><span class="fu">transf.iabt</span><span class="op">(</span><span class="va">xi</span><span class="op">)</span></span>
<span><span class="fu">transf.r2toz</span><span class="op">(</span><span class="va">xi</span><span class="op">)</span></span>
<span><span class="fu">transf.ztor2</span><span class="op">(</span><span class="va">xi</span><span class="op">)</span></span>
<span><span class="f