#include <stdio.h>

void printReal(REAL x) {
  if (sizeof(REAL) == sizeof(double))
    printf("%22.16e",x);
  else 
    printf("%15.9e",x);
}

int main() {
  REAL eps = 1.0, one = 1.0, fac = 0.5;
  while (eps*fac+one != one) eps *= fac; 

  printf("eps: "); printReal(eps); printf("\n");   
}