The anime Steins;Gate, Chaos;Head and Robotics;Notes all share the use of the semi-colon as part of their names. What is the reason for using the semi-colon within the titles of these anime?

The following anime share the use of the semicolon as part of their names:

1. Steins;Gate
2. Chaos;Head
3. Robotics;Notes
4. Occultic;Nine

What is the reason for using the semicolon within the titles of these anime?

The anime Steins;Gate, Chaos;Head and Robotics;Notes all share the use of the semi-colon as part of their names. However, what is the practical use of the semicolon convention here? The best answer that I could make out myself:

The semicolon in the names are used as a form of "pertaining to," however "not in possession of." Meaning--for example--"Steins" is related to "Gate" however, "Steins" is not in possession of "Gate." (This applies to the other two names as well.)

With this in mind, I also thought that rewording the names would also fit to explain my answer:

Gate of Steins

Head of Chaos

Notes of Robotics

In this case, we see that "Steins," "Chaos," and "Robotics" all are related to the the following words in the titles. Is this interpretation of the titles correct?

If my interpretation is correct, the meaning of the names and how they relate to the anime should stay exactly the same. The same, if not, what are the differences this would make?

The anime Steins;Gate, Chaos;Head and Robotics;Notes all share the use of the semi-colon as part of their names. What is the reason for using the semi-colon within the titles of these anime?