void problem_size ( int &chain_num, int &cr_num, int &gen_num, int &pair_num, 
  int &par_num );
void problem_value ( string *chain_filename, string *gr_filename, 
  double &gr_threshold, int &jumpstep, double limits[], int par_num, 
  int &printstep, string *restart_read_filename,
  string *restart_write_filename );
double prior_density ( int par_num, double zp[] );
double *prior_sample ( int par_num );
double sample_likelihood ( int par_num, double zp[] );