// -2.5             -2             -3      -2            -3             -3             -2
	// -2.6             -3             -3      -2            -3             -3             -2
}

func ExampleFloat_Copy() {
	var x, z big.Float

	x.SetFloat64(1.23)
	r := z.Copy(&x)
	fmt.Printf("a) r = %g, z = %g, x = %g, r == z = %v\n", r, &z, &x, r == &z)

	// changing z changes r since they are identical