It is known that the core of mathematics is natural numbers. And everything related to the natural number is interesting to mathematicians. In this paper, we draw parallels between natural numbers and elements of a non-numeric lexicographic sequence, Motzkin words (well-formed strings of parentheses and zeros). We will also talk about the decomposition of Motzkin words into pairs of parentheses (analogue of Prime Numbers). Finally, we will try to interest the reader in the elements of mathematical analysis on bracket expressions. The nesting procedure of parentheses is described by the author as the differentiation of the weight function. We will work a little with derivatives for bracket pairs and also give some differential equations.