function errors_test07 ( )

%*****************************************************************************80
%
%% ERRORS_TEST07
%
%  Licensing:
%
%    This code is distributed under the GNU LGPL license.
%
%  Modified:
%
%    21 August 2017
%
%  Author:
%
%    John Burkardt
%
  n = 4;

  fprintf ( 1, '\n' );
  fprintf ( 1, '+=============================================+\n' );
  fprintf ( 1, '|                                             |\n' );
  fprintf ( 1, '|  Exercise 7                                 |\n' );
  fprintf ( 1, '|                                             |\n' );
  fprintf ( 1, '|    A = [ -367296  -43199   519436  -954302 ]|\n' );
  fprintf ( 1, '|        [  259718 -477151  -367295 -1043199 ]|\n' );
  fprintf ( 1, '|        [  886731   88897 -1254026 -1132096 ]|\n' );
  fprintf ( 1, '|        [  627013  566048  -886732   911103 ]|\n' );
  fprintf ( 1, '|                                             |\n' );
  fprintf ( 1, '|    B = [ 1 ]                                |\n' );
  fprintf ( 1, '|        [ 1 ]                                |\n' );
  fprintf ( 1, '|        [ 1 ]                                |\n' );
  fprintf ( 1, '|        [ 0 ]                                |\n' );
  fprintf ( 1, '|                                             |\n' );
  fprintf ( 1, '|  Solve:                                     |\n' );
  fprintf ( 1, '|                                             |\n' );
  fprintf ( 1, '|    A * X = B                                |\n' );
  fprintf ( 1, '|                                             |\n' );
  fprintf ( 1, '|  Correct X:                                 |\n' );
  fprintf ( 1, '|                                             |\n' );
  fprintf ( 1, '|    8.86731088897E+17                        |\n' );
  fprintf ( 1, '|    8.86731088897E+11                        |\n' );
  fprintf ( 1, '|    6.27013566048E+17                        |\n' );
  fprintf ( 1, '|    6.27013566048E+11                        |\n' );
  fprintf ( 1, '|                                             |\n' );
  fprintf ( 1, '+=============================================+\n' );

  a = [
  -367296.0,  -43199.0,   519436.0,  -954302.0;
   259718.0, -477151.0,  -367295.0, -1043199.0;
   886731.0,   88897.0, -1254026.0, -1132096.0;
   627013.0,  566048.0,  -886732.0,   911103.0 ];

  b = [ 1.0; 1.0; 1.0; 0.0 ];

  x = a \ b;

  r8vec_print ( n, x, '  x=A\b solution:' );

  return
end
