Using the tools of praxeological analysis and didactical transposition analysis, the treatments of the Fundamental Theorem of Calculus in one Norwegian, Grade 13 textbook is analysed, with a particular focus on the development of the logos block of the FTC. The terms structure, functioning and utility, first introduced by Chevallard in 2022, is further to describe different dimensions of the mathematical object at stake. Through the analysis, a lack in the logos relating to the concept of integrability is identified in the textbook, and consequences of this is explored in relation to a set of tasks found in the book.