$a_1, a_2, a_3, a_4, a_5$ a) $a_1 < a_2$ $a_1 < a_3$ $a_1 < a_2 < a_3$ - NA $a_3 < a_1 < a_2$ # Problem 2 # Problem 3 ``` 1 2 3 |x|x|x|x| | | | |x| | | | |x| | | | |x| | |x| |x| | ```` {1,1} {2,2} {3,3} {1,3} {1,1} {3,3} {4,4} # Problem 4 $n+1 = 1$ $a^{n+1} = {a^0 * a^0}/{a^{0-1}}$ # Problem 7 ZB => Z, B ZZ => 3Z BB => Z, 2B --- 1st 200Z 800B x(Z B) + yB 2nd (Z B) + x(Z B) + (yB + y/2 Z) (x+y/2)Z, (x+y/2)B + y/2 B (x+y)Z, (x+y)B + yB which means, () --- z_gen(n) = ZB gen(min(n_b,_n_z)) + ZZ gen()3 + BB gen(n-1) b_gen(n) = ZB gen(n-1) + BB gen(n-1)2 Base case: $$ \begin{align} z_0 = 200 \\ b_0 = 800 \\ b_0 - z_0 ≥ 0 \\ \end{align} $$ Hyp: $$ b_n - z_n ≥ 0 $$ Induction step: Let $m_n = min(z_n, b_n)$. Since $b_n ≥ z_n$ by hypothesis, $m_n = z_n$. Then we have $$ \begin{align} z_{n+1} = m_n + \lfloor(z_n - m_n) / 2)\rfloor \cdot 3 + \lfloor(b_n - m_n) / 2 \rfloor \\ = m_n + \lfloor(b_n - m_n) / 2 \rfloor \\\text{(since z_n = m_n, the second floor evaluates to 0)} \end{align} $$ And, $$ b_{n+1} = m_n + \lfloor(b_n - m_n) / 2 \rfloor * 2 $$ Therefore, $$ \begin{align} b_{n+1} - z_{n+1} \\ = \lfloor(b_n - m_n) / 2 \rfloor \cdot 2 - \lfloor(b_n - m_n) / 2 \rfloor \\ = \lfloor(b_n - m_n) / 2 \rfloor \\ ≥ 0 \\ \text{ (since m_n = z_n and b_n - m_n ≥ 0)} \\ \end{align} $$