Олимпиадный тренинг

Задача 39083. Segments - 10


There are three segments on the number line: B = [25; 80], C = [60; 75] and D = [35; 70]. Specify the smallest possible length of such a segment A for which the logical expression
\(((x \in C) \neq (x \in B)) \rightarrow (x \in D) \ vee (x \in A)\)
true (i.e. takes the value 1) for any value of the variable x.