The solutions are all prepared well understood and as far as I've been working with it correctly.
In hindsight, the purchase was not absolutely necessary, I use it simply too rarely, and then I would also copy the library further bring.
Interesting is perhaps the purchase as Aufgabensammlung because actually before each answer the full question is which is to be used even without the textbook.
Conclusion: Mint game guide its acquisition is not necessary.