function h = reaction_twoway_conserved ( y )

%*****************************************************************************80
%
%% reaction_twoway_conserved evaluates a quantity that should be conserved.
%
%  Licensing:
%
%    This code is distributed under the GNU LGPL license.
%
%  Modified:
%
%    31 January 2021
%
%  Author:
%
%    John Burkardt
%
%  Input:
%
%    real Y(:,2): the variable values.
%
%  Output:
%
%    real H(:): the conserved quantity.
%
  w1 = y(:,1);
  w2 = y(:,2);

  h = w1 + w2;

  return
end
