1T=d f ld li
2V=x
3R=-1,1,1
4F=(abs(x) > 0) + \
5  2*(0 < abs(x)) + \
6  4*(abs(x) < 0) + \
7  8*(0 > abs(x))
8C=fp_greater(fp_abs(x), 0) + \
9  2*fp_less(0, fp_abs(x)) + \
10  4*fp_less(fp_abs(x), 0) + \
11  8*fp_greater(0, fp_abs(x))
12