J Strother Moore would disagree with you, the development of ACL [1] is going on from 40 years!<p>[1] <a href="http:&#x2F;&#x2F;www.cs.utexas.edu&#x2F;users&#x2F;moore&#x2F;acl2&#x2F;acl2-doc.html" rel="nofollow">http:&#x2F;&#x2F;www.cs.utexas.edu&#x2F;users&#x2F;moore&#x2F;acl2&#x2F;acl2-doc.html</a>