ng alter-alter relations/ edges.</p></dd>


<dt>aa.regex</dt>
<dd><p>A Perl regular expression with name capture,
intended to be run on column names and capturing via named
capture the following regex groups: <code>"attr"</code>, <code>"src"</code>, and
<code>"tgt"</code>, representing the edge attribute being captured, the
source (or the first alter identified), and the target (or the
second alter identified) of the edge, respectively. See <code><a href="https://rdrr.io/r/base/regex.html" class="external-l