function A = mac2_inc ( )

%*****************************************************************************80
%
%% mac_inc2() returns the incidence matrix for MacCormick's example 2.
%
%  Discussion:
%
%    This matrix appears on page 33 of the reference.
%
%  Licensing:
%
%    This code is distributed under the MIT license.
%
%  Modified:
%
%    01 March 2020
%
%  Author:
%
%    John Burkardt
%
%  Reference:
%
%    John MacCormick,
%    Nine Algorithms That Changed the Future: The Ingenious Ideas that 
%    Drive Today's Computers,
%    Princeton University Press,
%    ISBN-13: 978-0691158198.
%
%  Output:
%
%    integer A(16,16), the incidence matrix.
%
  A = zeros ( 16, 16 );

  A(1,2) = 1.0;
  A(1,3) = 1.0;
  A(1,6) = 1.0;
  A(2,4) = 1.0;
  A(3,4) = 1.0;
  A(3,5) = 1.0;
  A(4,5) = 1.0;
  A(5,7) = 1.0;
  A(5,8) = 1.0;
  A(6,5) = 1.0;
  A(6,7) = 1.0;
  A(7,15) = 1.0;
  A(8,7) = 1.0;
  A(8,9) = 1.0;
  A(8,10) = 1.0;
  A(9,10) = 1.0;
  A(10,7) = 1.0;
  A(10,11) = 1.0;
  A(10,12) = 1.0;
  A(10,13) = 1.0;
  A(10,14) = 1.0;
  A(11,15) = 1.0;
  A(12,15) = 1.0;
  A(13,15) = 1.0;
  A(14,15) = 1.0;
  A(15,16) = 1.0;
  A(16,1) = 1.0;

  return
end
