Minkowski's question-mark function

Minkowski's question-mark function, denoted as \( ?(x) \), is a special real-valued function defined on the interval \([0, 1]\), which is particularly interesting in the context of the theory of continued fractions and number theory. The function was introduced by Hermann Minkowski in 1904. ### Definition: The function \( ?(x) \) maps numbers in the interval \([0, 1]\) based on their continued fraction expansions.