ion and Refinement This chapter focuses on relationships between models known as abstraction and refinement. These terms are symmetric in that the statement “model A is an abstraction of model B” means the same thing as “model B is a refinement of model A.” As a general rule, the refinement model B has more detail than the abstraction A, and the abstraction is simpler, smaller, or easier to und...

Fred Halliday saw revolution and war as the dual motors of modern international order. However, while war occupies a prominent place in International Relations (IR), revolutions inhabit a more residual location. For Halliday, this is out of keeping with their impact – in particular, revolutions offer a systemic challenge to existing patterns of international order in their capacity to generate ...

Solution 1.1.1. The prime factorization of 720 is 2 · 3 · 5. If we look only at the prime factors of x, y, z, we see that the exponents of 2 in the factorizations of x, y, z must sum to 4, the exponents of 3 must sum to 2, and the exponents of 5 must sum to 0. The number of possible triples (a, b, c) that correspond to the exponents of 2 in the prime factorizations of x, y, z is simply the numb...