Dumb accumulated persistence hacking to speed up elementary-bounders.lisp

git-svn-id: http://acl2-books.googlecode.com/svn/trunk@2559 303c5b2c-9740-0410-b014-fd8f9db7be32
Quoting :doc note-6-5:

  The form (reset-prehistory nil) now is a no-op if [state] global
  'skip-reset-prehistory has a non-nil value. Thanks to Sol Swords
  for requesting this feature (in support of infrastructure for
  certifying the [community-books]).


git-svn-id: http://acl2-books.googlecode.com/svn/trunk@2560 303c5b2c-9740-0410-b014-fd8f9db7be32
Added pointer to books/demos/ directory/.

git-svn-id: http://acl2-books.googlecode.com/svn/trunk@2561 303c5b2c-9740-0410-b014-fd8f9db7be32
Adding new directory for challenge problem from Yan Peng.

git-svn-id: http://acl2-books.googlecode.com/svn/trunk@2562 303c5b2c-9740-0410-b014-fd8f9db7be32
Oops, fixed copy-and-paste error in header.

git-svn-id: http://acl2-books.googlecode.com/svn/trunk@2563 303c5b2c-9740-0410-b014-fd8f9db7be32