-- May 8 In-Class Exercise
for any y in L, there must be a z in L' (trimmed list) satisfy y/(1+delta) <= z <=y.
for delta = 0.1:
when y = 50, we put 50 in L' to satisfy the inequality. L' = {50}
when y = 51, 46.4 <= z <=51, 50 satisfies.
when y = 55, we need z s.t 50 <= z <=55, 50 satisfies.
when y = 70, we need z s.t. 63.6 <= z <= 70, so we put 70 in L'. L' = {50, 70}
when y = 71, we need z s.t. 64.5 <= z <= 71, 70 satisfies.
when y = 82, we need z s.t. 74.5 <= z <= 82, we put 82 in L'. L' = {50, 70, 82}
when y = 83, we need z s.t. 75.45 <= z <= 83, 82 satisfies.
when y = 84, we need z s.t. 76.36 <= z <= 84, 82 satisfies.
when y = 99, we need z s.t. 90 <= z <= 99, we put 99 in L'.
Finally L' = {50, 70, 82, 99}
for any y in L, there must be a z in L' (trimmed list) satisfy y/(1+delta) <= z <=y.
for delta = 0.1:
when y = 50, we put 50 in L' to satisfy the inequality. L' = {50}
when y = 51, 46.4 <= z <=51, 50 satisfies.
when y = 55, we need z s.t 50 <= z <=55, 50 satisfies.
when y = 70, we need z s.t. 63.6 <= z <= 70, so we put 70 in L'. L' = {50, 70}
when y = 71, we need z s.t. 64.5 <= z <= 71, 70 satisfies.
when y = 82, we need z s.t. 74.5 <= z <= 82, we put 82 in L'. L' = {50, 70, 82}
when y = 83, we need z s.t. 75.45 <= z <= 83, 82 satisfies.
when y = 84, we need z s.t. 76.36 <= z <= 84, 82 satisfies.
when y = 99, we need z s.t. 90 <= z <= 99, we put 99 in L'.
Finally L' = {50, 70, 82, 99}