WARNING: The makefile mechanism under books/nonstd/ isn't currently set up to
use ACL2(r) automatically.  When you execute make, be sure to do so from this
directory and use a command of the form

  make ACL2=your_saved_acl2r

This is the books directory for ACL2(r), the extension of ACL2 supporting the
real numbers via non-standard analysis, which was conceived and first
implemented by Ruben Gamboa in his Ph.D. dissertation work.  This directory is
subdirectory books/nonstd of the top-level ACL2 directory.

The subdirectories here include most of those from subdirectory books of the
top-level ACL2 directory, referred to below as ../../books.  The directories
below that do not have corresponding directories under ../../books rely on
ACL2(r); they are expected to contain books all of which are certifiable in
ACL2(r), but not necessarily ACL2.

Before certifying any of these books, it is necessary to build ACL2(r).  This
can be accomplished on systems understanding the make command (e.g., Unix) by
standing in the top-level ACL2 directory and executing "make small-acl2r".

After that, it is necessary to create links to books in ../../books.  This may
be accomplished by standing in the directory of this README file (i.e.,
books/nonstd under the top-level ACL2 directory) and issuing the following
command.

make links

Then the books most likely to be of use under here, i.e., under books/nonstd,
may be certified using the command "make" in this directory, or if it is
desired to certify all the books under here (including the two case studies
under case-studies/), "make all-plus".

The modifications in ACL2(r) to ACL2 are only minimally documented.  See :doc
REAL for more information.
