The Mathematics Study Program, Faculty of Science and Technology, UIN Sunan Kalijaga Yogyakarta, once again held an Applied Mathematics Colloquium on Friday, November 21, 2025, in Room 104 of the Faculty of Science and Technology. The event, which ran from 9:00 to 11:00 a.m. Western Indonesian Time, featured a guest speaker from Germany, Prof. Axel Kilian from SES (Senior Expert Service) Germany.

On that occasion, Prof. Axel Kilian delivered a presentation entitled "The Game Tic-Tac-Toe 3D: An Example of Graph Theory and Game Theory." He explained how the three-dimensional version of Tic-Tac-Toe can serve as an interesting model for studying important concepts in graph theory and game theory. Through a systematic mathematical approach, the speaker demonstrated how optimal strategies in the game can be modeled, analyzed, and evaluated using graph structures and the concept of payoffs in game theory.

The colloquium was attended by lecturers and students of the Mathematics Study Program, particularly those majoring in Applied Mathematics. The participants' enthusiasm was evident in the numerous questions and discussions that arose during the Q&A session, particularly regarding the application of graph theory to solving strategic games and opportunities for further research in this area.

Through this activity, it is hoped that students will gain new insights into how applied mathematics concepts can be used to analyze simple phenomena such as games, while also opening broader research horizons in the field of modern applied mathematics.