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gfan(1)

NAME

   gfan - tool to compute Grbner fans and tropical varieties

SYNOPSIS

   gfan_tool [options]

   gfan _tool [options]

DESCRIPTION

   Gfan  is  a  software  package  for computing Grbner fans and tropical
   varieties.  These are polyhedral fans associated to polynomial  ideals.
   The  maximal  cones  of  a Grbner fan are in bijection with the marked
   reduced Grbner bases of its defining ideal. The software computes  all
   marked  reduced  Grbner  bases of an ideal. Their union is a universal
   Grbner basis. The tropical variety of a polynomial ideal is a  certain
   subcomplex  of  the Grbner fan. Gfan contains algorithms for computing
   this complex for general ideals and specialized algorithms for tropical
   curves,  tropical hypersurfaces and tropical varieties of prime ideals.
   In addition to the above core functions the package contains many tools
   which  are  useful  in  the  study of Grbner bases, initial ideals and
   tropical geometry.

   The complete list of tools is:

   bases, buchberger, combinerays, doesidealcontain,  fancommonrefinement,
   fanhomology,   fanlink,   fanproduct,  fansubfan,  genericlinearchange,
   groebnercone, groebnerfan, homogeneityspace, homogenize,  initialforms,
   interactive,   ismarkedgroebnerbasis,   krulldimension,   latticeideal,
   leadingterms,   list,    markpolynomialset,    minkowskisum,    minors,
   mixedvolume,    overintegers,    padic,   polynomialsetunion,   render,
   renderstaircase,   saturation,   secondaryfan,    stats,    substitute,
   symmetries,        tolatex,       topolyhedralfan,       tropicalbasis,
   tropicalbruteforce,        tropicalevaluation,        tropicalfunction,
   tropicalhypersurface,       tropicalintersection,      tropicallifting,
   tropicallinearspace,        tropicalmultiplicity,         tropicalrank,
   tropicalstartingcone, tropicaltraverse, tropicalweildivisor, version.

   Below  are  presented the generic options available with all tools. For
   specific options of a given tool, we refer to the help message of  that
   tool.

OPTIONS

   --help Display a help message describing the functionality of gfan_tool
          and the available specific options.

   --log1, --log2...
          Tell Gfan how much information to write to standard error  while
          a computation is running. These options are very useful when you
          wish to know if Gfan is making any progress in its computation.

   --stdin value
          Specify a file to use as  input  instead  of  reading  from  the
          standard input.

   --stdout value
          Specify  a  file  to  write  output to instead of writing to the
          standard output.

   --xml  Let polyhedral fans be output in an XML format instead of in the
          text format. (The XML files are not readable by Gfan.)

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