#ifndef _PPF_OPERATORS_
#define _PPF_OPERATORS_

double ppf_max_callback(double x, double y);
double ppf_sum_callback(double x, double y);
double ppf_sub_callback(double x, double y);
double ppf_exclude_callback(double x, double y);
bool ppf_geq_callback(double x, double y);
bool ppf_compare_callback(double x, double y);

#endif // _PPF_OPERATORS_


