function value = fu_integral ( d )

%*****************************************************************************80
%
%% fu_integral() is the integral of the test function for the [0,1]^D interval.
%
%  Discussion:
%
%    The same function, integrated over [-1,+1]^D, has an integral that is
%    2^D times larger.
%
%  Licensing:
%
%    This code is distributed under the MIT license.
%
%  Modified:
%
%    20 March 2019
%
%  Author:
%
%    John Burkardt.
%
%  Input:
%
%    integer D, the spatial dimension.
%
%  Output:
%
%    real VALUE, the integral value.
%
  value = ( 0.5 * erf ( 0.5 / sqrt ( 2.0 ) ) ) .^ d;

  return
end
