#ifndef _MATH_H #define _MATH_H double fabs (double x); float fabsf (float x); double floor (double x); float floorf (float x); double ceil (double x); float ceilf (float x); double fmod (double x, double y); float fmodf (float x, float y); double copysign (double x, double y); float copysignf(float x, float y); #endif