an idea on css selectors inheritance

idea by http://rip747.wordpress.com/2008/04/10/css3-css-variables-are-a-bad-idea-just-allow-us-to-call-other-selectors/

<style type="text/css">
.bold {font-weight:bold;}
.blue {color:blue;}
.testingagain {selectors:.bold, .blue;}
</style>
<p class="testingagain">testing this out</p>