#include <iostream>#include <cmath>#include <boost/numeric/linear_algebra/operators.hpp>#include <boost/numeric/linear_algebra/concepts.hpp>#include <libs/numeric/linear_algebra/test/algebraic_functions.hpp>#include <libs/numeric/linear_algebra/test/positive_real.hpp>// User defined data types and operatorsusing mtl::positive_real;# ifdef __GXX_CONCEPTS__  namespace math {       concept_map Monoid< add<positive_real>, positive_real > {};  }# endif int main(int, char* []) {    positive_real                a0(0.0), a2(2.0), a3(3.0), a4(4.0), a5(5.0);    math::add<positive_real>     my_add;       std::cout << "equal_results(a2,a5,  a3,a4, my_add) " 	      << mtl::equal_results(a2,a5,  a3,a4, my_add)  << '\n';     std::cout << "equal_results(a2,a4,  a3,a4, my_add) " 	      << mtl::equal_results(a2,a4,  a3,a4, my_add)  << '\n';    std::cout << "identity_pair(a2,a4, my_add) " 	      << mtl::identity_pair(a2,a4, my_add)  << '\n';    std::cout << "identity_pair(a0,a0, my_add) " 	      << mtl::identity_pair(a0,a0, my_add)  << '\n';    return 0;}