Quoting :doc note-6-4:

  There are new analogues of [add-include-book-dir] and
  [delete-include-book-dir]: [add-include-book-dir!] and
  [delete-include-book-dir!], respectively. The new utilities are
  similar to their existing counterparts, except that their effects
  are not [local] to enclosing [books] or [encapsulate] events.
  Thanks to Shilpi Goel for requesting this enhancement.


git-svn-id: http://acl2-devel.googlecode.com/svn/trunk@1165 5d84a466-a78b-0930-a311-59b22171a541