README file for lrslib : reverse search vertex enumeration program/CH package
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Documentation is currently being maintained at the URL:

http://cgm.cs.mcgill.ca/~avis/lrs.html
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2010.5.7  incidence no longer resets printcobasis frequency to zero. 
          If the printcobasis n option is used, the frequency will be n.
          Otherwise the default n=0 is used, and cobasis is printed only for lexmin bases.
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2010.4.26 bug when incidence and nonnegative options used together reported by 
          Jochen Koenemannkfix was fixed. 
          Bug in fourier reported by Laszlo David for input which is not full
          dimensional. I am temporarily removing fourier from distribution.
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2009.12.2 bug fix for redund caused problems in nash, reported by James Heather.
          Hopefully this new version solves both issues.
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2009.9.10  bug in redund reported by Alden Walker, when linearities are redundant, has been fixed.
           It is now under test, so please report any bugs!
           this bug also can cause printcobasis option to be incorrect for lrs under this condition. 
           Problems still seem to arise in fourier from time to time, so please report any anomalities.
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2009.2.5    bug in fourier when using linearity option pointed out by Conor Meagher.  Option disabled.
            2nash driver uses two processors to run nash with input files in both orders.
            terminates when first process terminates. Thanks again to Conor for this.
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2007.6.6    printcobasis output line modified to give also in_det
            det= the determinant of the current basis, which is always integer.
            in_det= the determinant of the input rows corresponding to the current basis. lrs rescales input rows if they are rational or have a common divisor, so in these cases det and in_det are different.
For V-representation, the volume will be the sum of the in_det of
each basis, divided by the dimension (n-1)!
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2006.10.31   Modified code for restartpivots, to allow DB to do something.
             Estimator now provides estimate of running time=time*bases/tree nodes
             Triangulation printed if getvolume and verbose options used
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2006.10.11   Bug fix for nash, and inclusion of polytope version
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             available by using setupnash2
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2006.3.1 incidence option now can be used compatibly with printcobasis n 
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2006.2.14
Version 4.2b

Bug fixed related to memory allocation for linearity reported by David Haws.
If you use the linearity option, you should upgrade to this version.

In the case of inconsistent linearities, the first inconsistent linearity
is now reported before termination.

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2005.11.20
Version 4.2a

Bug fixed relating to miscaled lp dual variables output when lponly set

maxoutput n   Option limits output lines to n: either rays+vertices, or facets

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2005.6.1
Version 4.2 with two new drivers:

nash.c  which computes all Nash equilibria of a two person non-cooperative game,
        and uses setupnash.c to create the input files.

fourier.c  which does Fourier elimination on an H-representation to project it to
           a lower dimensional space. Contributed by Tallman Nkgau.

Other changes: lrs with the lponly option now provides dual variables for the 
        optimum solution.

Bug fix to mpdouble (reported by several users.)

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2004.9.23
Version 4.2 updated with a patch from Bremner that has something to do with C++.

2003.10.24

Version 4.2 which appears here is a prerelease version, is not fully tested,
and will be modified frequently. However you are more than welcome to try
it - please report any bugs! Merci beaucoup.

2002.10.28

lrslib v.4.2        minor modifications to v.4.1

This is a pre-release for test purposes. Please report bugs!
Nonnegative option was fixed to allow input where origin is not necessarily
a vertex.
A memory leak was fixed.
A quiet mode is added - compile with LRS_QUIET set.

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2001.6.20

lrslib v.4.1

lpsolve like procedures to build input data added. Demo programs are:

vedemo.c    vertex enumeration
chdemo.c    facet enumeration
lpdemo.c    linear programs

They can be build using: make demo

Proper garbage collection implemented to clean up after each problem has been
solved. See

http://cgm.cs.mcgill.ca/~avis/C/lrslib/lrslib.html 

for documentation.

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2000.6.14

Various binaries are available in the directory binaries.

Currently available:

binaries/debian        Debian Linux      
binaries/sun           Sun Ultra Sparc
binaries/win98         Windows 95/98

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2000.6.14

lrslib v.4.0 which
supercedes all previous versions of the programs lrs and redund.
New Features:
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1. Library version allows customization of the search function, access to the
output as it is produced, and access to lrs from other programs.

2. Problems need no longer be in full dimension. This allows the
input of equations, partial enumeration on facets, ridges etc.

3. Choice of arithmetic packages. Currently available are:

   lrsmp     Extended precision arithmetic used in previous releases
  
   lrslong   Fixed length long integer arithmetic. No overflow checking
             but 5-10 times faster.

   lrsgmp    Requires preinstallation of GNU GMP package, available at
             http://www.swox.com/gmp/

  The standard "make all" gives lrs/redund with lrsmp, and lrs1/redund1 with lrslong. 
 
4. redund was completely rewritten and is faster than before. The previous
   version did not remove redundancy in the starting basis and should be
   discarded. 


Installation:
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1. From website go to "Download" and retrieve the file lrslib-040.tar.gz

2. Unpack with:

   % gunzip lrslib-040.tar.gz
   % tar xvf lrslib-040.tar

3. Go to the new directory

   % cd lrslib-040

4. make binaries by typing
   
   % make all               (most 32 bit unix machines)

or

  % make all64              (64 bit integer machines such as DEC Alpha)

If the make fails, it is usually due to timing and/or interrupt handling
routines. In this case try:

  % make nosigs

5. If successful you should get binaries: lrs redund lrs1 redund1

6. Test the program lrs by typing:

   lrs cube.ine

and you should get output resembling the file cube.ext

7. You will find additional test files in the directories: ine and ext

8. For GNU gmp library, edit the makefile to set the INCLUDE and LIB paths for
   the location of the gmp libarary, and type:

   %make gmp

   You should get binaries glrs and gredund
