NAME

       tred - transitive reduction filter for directed graphs

SYNOPSIS

       tred [ -v?  ] [ files ]

DESCRIPTION

       tred computes the transitive reduction of directed graphs, and prints the resulting graphs
       to standard output.  This removes edges implied by transitivity.  Nodes and subgraphs  are
       not otherwise affected.  The ``meaning'' and validity of the reduced graphs is application
       dependent.  tred is particularly useful as a preprocessor to  dot  to  reduce  clutter  in
       dense layouts.

       Undirected graphs are silently ignored.

OPTIONS

       The following options are supported:

       -v     Verbose output.

       -?     Print usage information.

OPERANDS

       The following operand is supported:

       files   Names  of files containing 1 or more graphs in dot format.  If no files operand is
               specified, the standard input will be used.

BUGS

       Using bitmaps internally would substantially decrease running time.

DIAGNOSTICS

       If a graph has cycles, its transitive reduction is not uniquely  defined.   In  this  case
       tred emits a warning.

AUTHORS

       Stephen C. North <north@research.att.com>
       Emden R. Gansner <erg@research.att.com>

SEE ALSO

       gc(1), dot(1), acyclic(1), gvpr(1), gvcolor(1), ccomps(1), sccmap(1), libgraph(3)

                                          21 March 2001                                   TRED(1)