NOTE-2-8-OTHER.html -- ACL2 Version 6.3

### NOTE-2-8-OTHER

ACL2 Version 2.8 Notes on Miscellaneous Changes

    Major Section:  NOTE-2-8

Execution of `table` events has been sped up in many cases by avoiding excessive consing.

ACL2 now warns if `:``rewrite` (or `:``definition`) rules contain free variables on the right-hand side. Thanks to Dave Greve for raising this issue.

Emacs file `emacs/emacs-acl2.el` has been updated to better comprehend the notion of the ``ACL2 shell'', which is the buffer to which ACL2 forms are written by commands defined in the above file. Thus, command `control-t e` has been modified always to write to the ACL2 shell (which is `"*shell*"` by default), and the following new commands have been defined.

> o control-t c
> Set the ACL2 shell to the current buffer. o control-t b
> Change to the ACL2 shell.

The commands `:``pl` and `:``pr` may now be given a macro name that corresponds via the `macro-aliases-table` to a function name, so that for example `:pl append` is treated the same as `:pl binary-append`. A more interesting improvement, for `:pl` only, is that `:pl` may now take any term. When `:pl` is given a term other than a symbol, it will print all rewrite rules that match that term. Thanks to David Russinoff, Robert Krug, and Bill Legato for getting this going.

A new function, `pkg-witness`, returns a symbol in the given package.

The installation instructions have been updated, for example to give more guidance on obtaining Lisp implementations and to mention the acl2-help mailing list.

Jared Davis has suggested some symbols to be added to `*acl2-exports*`, and we have done so. Thanks, Jared.

> o `MFC` (used in `syntaxp` and `extended-metafunctions`; thanks also to Robert Krug for this one) o `ID`, `CLAUSE`, `WORLD`, and `STABLE-UNDER-SIMPLIFICATIONP` (used in `computed-hints`) o `SET-DEFAULT-HINTS`

The command `:``pe` has been improved so that when the event is inside an included book, the path of included books (from the top-level book down to the one containing the event) is shown. Thanks to Eric Smith (perhaps among others) for pointing out the utility of this improvement.

A new release of the rtl library has been included: `books/rtl/rel4/`. See the `README` file in that directory.