double pow_di(ap, bp)double *ap;long int *bp;{double pow, x;long int n;pow = 1;x = *ap;n = *bp;if(n != 0)	{	if(n < 0)		{		if(x == 0)			{			return(pow);			}		n = -n;		x = 1/x;		}	for( ; ; )		{		if(n & 01)			pow *= x;		if(n >>= 1)			x *= x;		else			break;		}	}return(pow);}