// Operate on numbers of different precision.
	var x, y, z big.Float
	x.SetInt64(1000)          // x is automatically set to 64bit precision
	y.SetFloat64(2.718281828) // y is automatically set to 53bit precision
	z.SetPrec(32)
	z.Add(&x, &y)
	fmt.Printf("x = %.10g (%s, prec = %d, acc = %s)\n", &x, x.Text('p', 0), x.Prec(), x.Acc())
	fmt.Printf("y = %.10g (%s, prec = %d, acc = %s)\n", &y, y.Text('p', 0), y.Prec(), y.Acc())

			return errors.New("Float.GobDecode: buffer too small for finite form float")
		}
		z.exp = int32(byteorder.BeUint32(buf[6:]))
		z.mant = z.mant.setBytes(buf[10:])
	}

	if oldPrec != 0 {
		z.mode = oldMode
		z.SetPrec(uint(oldPrec))
	}

	if msg := z.validate0(); msg != "" {
		return errors.New("Float.GobDecode: " + msg)
	}

	return nil
}

// MarshalText implements the [encoding.TextMarshaler] interface.

	if mode == ToNearestAway {
		panic("not yet implemented")
	}
	if mode == ToNearestEven && rbit == 1 && (sbit == 1 || sbit == 0 && bit0 != 0) || mode == AwayFromZero {
		// round away from zero
		f.SetMode(ToZero).SetPrec(prec)
		f.Add(f, Bits{int(r) + 1}.Float())
	}
	return f
}

// Float returns the *Float z of the smallest possible precision such that
// z = sum(2**bits[i]), with i = range bits. If multiple bits[i] are equal,