Non-locally unlink keyword for :dir argument of ld and include-book
Please see delete-include-book-dir, which has completely
analogous syntax and semantics, but is used for removing associations
previously placed by add-include-book-dir. By contrast,
delete-include-book-dir! removes associations previously placed by
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 is essentially a table event that updates the table
include-book-dir!-table, which associates keywords with absolute
pathnames. However, as with delete-include-book-dir, direct table
updates are disallowed; you must use delete-include-book-dir! to remove
from the table and add-include-book-dir! to add to the table.
It is illegal to call delete-include-book-dir! in a local
context. For an explanation, see add-include-book-dir!.