1.1.2 `phc.phc'
---------------

phc.phc(S|proc=P)
     ::  Ask PHC pack to find all the roots in the complex torus of the
     given systems of polynomials S

RETURN
     Void

P
     Number

S
     List

   *  The server calls PHC pack to solve a system of algebraic
     equations S     by homotopy methods.      PHC pack has been
     developed by Jan Verschelde. See     `www.mth.msu.edu/~jan' for
     the original distribution.      The original PHC pack can choose
     several strategies to solve,     but our phc interface uses only
     black-box solver, which is general     and automatic but is not
     efficient. So, if you fails by our interface,     try the other
     strategies via the original user interface.

   * phc generates working files  tmp.phc.out.pid, tmp.input.*,
     tmp.output.*.      Here, pid the process number of the server.
     The file `tmp.output.*' contains details informations on how PCH
     pack     solves the system.

   * The number of variables and the number of equations `length(S)'
     must agree.

Algorithm: Jan Verschelde, PHCpack: A general-purpose solver for
polynomial systems by homotopy continuation".  ACM Transaction on
Mathematical Softwares, 25(2): 251-276, 1999.

     [232] P = phc.start();
     0
     [233] phc.phc([x^2+y^2-4,x*y-1]|proc=P);
     The detailed output is in the file tmp.output.*
     The answer is in the variable Phc.
     0
     [234] Phc;
     [[[-1.93185,0],[-0.517638,0]],
      [[0.517638,0],[1.93185,0]],
      [[-0.517638,0],[-1.93185,0]],
      [[1.93185,0],[0.517638,0]]]

      [[x=[real, imaginary], y=[real,imaginary]],  the first solution
       [x=[real, imaginary], y=[real,imaginary]],  the second solution
       ...

Reference
     `ox_launch', `phc.start', `$(OpenXM_HOME)/bin/lin_phcv2'(original
     PHC pack binary for linux)

