These theses can be expressed more concisely by means of the symbolism in Figure 8.1, which also makes it possible to compare different versions of OT with CT.

Elements that necessarily belong to an act are within boxes with unbroken sides. Elements that belong to an act only contingently, i.e. elements that the act can have or can lack, are within boxes with broken sides. An arrowhead '-+' in front of a box indicates that the thing in the box is the one to which the act is directed The theories of Frege and Husserl have precisely the same structure:

The fine details of Hussed's theory, e.g. his distinction between quality and matter or between ideal and 'real' content, are not shown by this symbolism, and the same holds true of Frege's distinction between idea and sense. Still, the symbolism exhibits the basic structure of the two respective theories. Any theory that shares this structure can be called a version of CT. This analysis takes place on a high level of abstraction. We do not claim that there are no significant differences between Husserl and Frege in semantics and ontology; we can only claim that the basic structure of their theories is the same.