associate directory to keyword for include-book's :dir argument
Major Section:  EVENTS

Example Form:
(add-include-book-dir :smith "/u/smith/")
 ; For (include-book "foo" :dir :smith), prepend "/u/smith/" to "foo".

General Form: (add-include-book-dir kwd dir)

where kwd is a keywordp and dir is the absolute pathname (see pathname) of a directory. The effect of this event is to modify the meaning of the :dir keyword argument of include-book as indicated by the examples above, namely by associating the indicated directory with the indicated keyword for purposes of the include-book :dir argument. See delete-include-book-dir for how to undo this effect.

Caveat: The keyword :system cannot be redefined. It will always point to the absolute pathname of the distributed books directory, which by default is immediately under the directory where the ACL2 executable was originally built (see include-book, in particular the discussion there of ``books directory''). Thus, if you move the distributed books directory after building the executable, :system will likely not work for you. (See the use of ACL2_BOOKS_DIR in the top-level Makefile if you want the executable built so that :system points to a particular books/ directory other than the default.)

Note: This is an event! It does not print the usual event summary but nevertheless changes the ACL2 logical world and is so recorded.

This macro generates a call (table acl2-defaults-table :include-book-dir-alist ...) and hence is local to any books in which is occurs; see acl2-defaults-table.