       explicitly or implicitly by
            <code class="computeroutput"><a class="link" href="make_expr_idp89526624.html" title="Function make_expr">proto::make_expr</a>()</code>,
            <code class="computeroutput"><a class="link" href="unpack_expr_idp89543264.html" title="Function unpack_expr">proto::unpack_expr</a>()</code>,
            or Proto's operator overloads &#8212; Proto will use the domains of the child expressions to
            compute the domain of the parent. It is done in such a w