A. Cimatti, F. Fraternali, and C. Nipoti. (2019)cite arxiv:1912.06216Comment: 17 pages, 3 figures, first introductory chapter of the textbook published by Cambridge University Press. For more information https://decdb4ae-c884-4971-9114-5f11b6929fd9.filesusr.com/ugd/f44359_26d2207ea96e4f359636feb5b7473336.pdf.