INCLUDE-BOOK

Major Section:  EVENTS

Examples:
(include-book "my-arith")
(include-book "/home/smith/my-arith")
(include-book "/../../my-arith")


General Form:
(include-book file :load-compiled-file action  ; [default :warn]
                   :uncertified-okp t/nil      ; [default t]
                   :defaxioms-okp t/nil        ; [default t]
                   :skip-proofs-okp t/nil      ; [default t]
                   :ttags ttags                ; [default nil]
                   :dir directory
                   :doc doc-string)

If there is a compiled file for the book that was created more recently than the book itself and the value action of the :load-compiled-file argument is not nil, or is omitted, then the compiled file is automatically loaded; otherwise it is not loaded. If action is t then the compiled file must be loaded or an error will occur; if action is :warn (the default) then a warning will be printed; if action is :try then no warning will be printed; and if action is :comp then the file will be immediately compiled (if the compiled file does not already exist) and loaded. The action :comp! is handled just like :comp, with two exceptions: compilation always takes place because the old compiled file is first deleted, and executable counterparts are also compiled (in analogy to value :all for the compile-flg argument of certify-book; see certify-book). Certify-book can also be used to compile a book; thus, :comp and :comp! do the same sort of compilation as certify-book when the latter is given a compile-flg of t or :all, respectively. An effect of compilation is to speed up the execution of the functions defined within the book when those functions are applied to specific values. Compilation can also remove tail recursion, thus avoiding stack overflows. The presence of compiled code for the functions in the book should not otherwise affect the performance of ACL2. See guard for a discussion. NOTE: the :load-compiled-file argument is not recursive; that is, calls of include-book that are inside the book supplied to include-book will use their own :load-compiled-file arguments (default :warn), not the :load-compiled-file argument for the enclosing book.

The three -okp arguments, :uncertified-okp, defaxioms-okp, and skip-proofs-okp, determine the system's behavior when the book or any subbook is found to be uncertified, when the book or any subbook is found to contain defaxiom events, and when the book or any subbook is found to contain skip-proofs events, respectively. All three default to t, which means it is ``ok'' for the condition to arise. In this case, a warning is printed but the processing to load the book is allowed to proceed. When one of these arguments is nil and the corresponding condition arises, an error is signaled and processing is aborted. Exception: :uncertified-okp is ignored if the include-book is being performed on behalf of a certify-book.

The keyword argument :ttags may normally be omitted. A few constructs, used for example if you are building your own system based on ACL2, may require it. See defttag for an explanation of this argument.

Include-book is similar in spirit to encapsulate in that it is a single event that ``contains'' other events, in this case the events listed in the file named. Include-book processes the non-local event forms in the file, assuming that each is admissible. Local events in the file are ignored. You may use include-book to load several books, creating the logical world that contains the definitions and theorems of all of them.

If any non-local event of the book attempts to define a name that has already been defined -- and the book's definition is not syntactically identical to the existing definition -- the attempt to include the book fails, an error message is printed, and no change to the logical world occurs. See redundant-events for the details.

When a book is included, the default defun-mode (see default-defun-mode) for the first event is always :logic. That is, the default defun-mode ``outside'' the book -- in the environment in which include-book was called -- is irrelevant to the book. Events that change the defun-mode are permitted within a book (provided they are not in local forms). However, such changes within a book are not exported, i.e., at the conclusion of an include-book, the ``outside'' default defun-mode is always the same as it was before the include-book.

Unlike every other event in ACL2, include-book puts a burden on you. Used improperly, include-book can be unsound in the sense that it can create an inconsistent extension of a consistent logical world. A certification mechanism is available to help you carry this burden -- but it must be understood up front that even certification is no guarantee against inconsistency here. The fundamental problem is one of file system security. See certificate for a discussion of the security issues.

After execution of an include-book form, the value of acl2-defaults-table is restored to what it was immediately before that include-book form was executed. See acl2-defaults-table.

Distributed Books Directory. We refer to the ``books directory'' of an executable image as the full pathname string of the books directory associated with :dir :system for that image. This is where the distributed books directory should reside. By default, it is the books/ subdirectory of the directory where the sources reside and the executable image is thus built. If those books reside elsewhere, the environment variable ACL2_SYSTEM_BOOKS can be set to the books/ directory under which they reside (a Unix-style pathname, typically ending in books/ or books, is permissible). In most cases, your ACL2 executable is a small script in which you can set this environment variable just above the line on which the actual ACL2 image is invoked.

This concludes the guided tour through books. See set-compile-fns for a subtle point about the interaction between include-book and on-the-fly compilation. See certify-book for a discussion of how to certify a book.

:cited-by Programming