_function.html"><a href="230_R_function.html#environment"><i class="fa fa-check"></i><b>23.2</b> Environment</a></li>
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<li class="chapter" data-level="24" data-path="240_na_nan_inf.html"><a href="240_na_nan_inf.html"><i class="fa fa-check"></i><b>24</b> NA NaN Inf NULL</a>
<ul>
<li class="chapter" data-level="24.1" data-path="240_na_nan_inf.html"><a href="240_na_nan_inf.html#notations-of-na-nan-inf"><i class="fa fa-check"></i><b>24.1</b> Notations of NA NaN Inf</a></li>
<li class="chapter" data-le