// In header: <boost/numeric/odeint/stepper/implicit_euler.hpp>

template<typename ValueType, typename Resizer = initially_resizer> 
class implicit_euler {
public:
  // types
  typedef ValueType                                           value_type;          
  typedef value_type                                          time_type;           
  typedef boost::numeric::ublas::vector< value_type >         state_type;          
  typedef state_wrapper< state_type >                         wrapped_state_type;  
  typedef state_type                                          deriv_type;          
  typedef state_wrapper< deriv_type >                         wrapped_deriv_type;  
  typedef boost::numeric::ublas::matrix< value_type >         matrix_type;         
  typedef state_wrapper< matrix_type >                        wrapped_matrix_type; 
  typedef boost::numeric::ublas::permutation_matrix< size_t > pmatrix_type;        
  typedef state_wrapper< pmatrix_type >                       wrapped_pmatrix_type;
  typedef Resizer                                             resizer_type;        
  typedef stepper_tag                                         stepper_category;    
  typedef implicit_euler< ValueType, Resizer >                stepper_type;        

  // construct/copy/destruct
  implicit_euler(value_type = 1E-6);

  // public member functions
  template<typename System> 
    void do_step(System, state_type &, time_type, time_type);
  template<typename StateType> void adjust_size(const StateType &);

  // private member functions
  template<typename StateIn> bool resize_impl(const StateIn &);
  void solve(state_type &, matrix_type &);
};