Commentary
AI Technology Maps Relate to Oneʼs View of the World ……………………………………………………………… Koji Morikawa 411
Special Issue: “Machine Learning with Discrete Structures”
Editorʼs Introduction to “Machine Learning with Discrete Structures” ……………………………………………… Mahito Sugiyama 412
Expressive Power of Graph Neural Networks ……………………………………………………………………………… Ryoma Sato 413
Advances in Graph Kernels …………… Kazu Ghalamkari, Mahito Sugiyama, Leslie OʼBray, Bastian Rieck and Karsten Borgwardt 421
Molecular Graph Generation Using Machine Learning …………………………………………………………………Hiroshi Kajino 430
T-PRISM: A System Integrating Deep Learning and Logic Programming …………………………… Ryosuke Kojima, Taisuke Sato 437
Sentential Decision Diagram and Machine Learning ………………………………………………………………… Masaaki Nishino 445
Order Structure and Statistical Models ……………………………………………………………………………… Mahito Sugiyama 454
Mutations of Disjoint Cycle Set Corresponding to Cluster Algebra in Triangulated Surfaces
─ Cluster Algebra for Data Science ─ …… Ryo Yamada, Shun Kinoshita, Minori Wada, Kazushi Mimura and Mahito Sugiyama 461
Special Issue: “Interaction via Virtual Space”
Editorsʼ Introduction to “Interaction via Virtual Space” …………………………………… Yoshimasa Tawatsuji and Sho Yamamoto 470
A Learning Interaction as Information Sharing in Class via Virtual Space …………………………………………… Sho Yamamoto 472
Virtual Space as Externalization of Thinking
─ From Viewpoint of Learning Support ─ ……………………………………………………………………… Tsukasa Hirashima 476
Towards Realization of Deep Interaction in Individual Learning Environment ……………………………………… Tatsunori Matsui 480
Designing Learning Environments That Supports Learner Interactions Mediated by Virtual Space
─ From the Viewpoint of Emergent Division of Labor ─ ……………………………………………………… Toshio Mochizuki 484
Two Types of Uncanny Valley in Pedagogical Agent …………………………………………………………… Yoshimasa Tawatsuji 488
Anthropomorphic Agents Supporting Contextual Reality toward Behavior Modification
─ Robots, Virtual Agents, and Virtual Mind in Applications ─ ………………………………………………… Tomoko Yonezawa 492
Breaking Online Learning Open …………………………………………………………………………………… Akihiro Kashihara 496
Lecture Series: “AI Philosophy Map”（3）
Exploring Feasibility of Constructing New Intelligence and Awareness Based on Bergsonʼs “Time Scale”（Part 1）
……………… Tadahiro Taniguchi, Yasushi Hirai and Yoji Kiyota, Moderator: Youichiro Miyake, Composition: Takako Ouchi 500
My Bookmark
Urban Computing ─ World Trend of Data Set in Urban Space ………………………………………………… Yoshihide Sekimoto 512
Students Forum（106）
The Actual State of Student Research Activities in COVID-19
…………………………………………………………… Mamoru Yoshizoe, Kense Todo, Yusuke Nishimura and Yuki Kuroda 521
Conference Reports
NeurIPS 2020（The 34th Conference on Neural Information Processing Systems）
………………………………………………………………………………… Sho Takase, Riku Sakamoto and Tsuyoshi Okita 527
IJCAI-PRICAI 2020（The 29th International Joint Conference on Artificial Intelligence and
the 17th Pacific Rim International Conference on Artificial Intelligence） …………………………………… Yoshitaka Sakamoto 532
Book Review
Tadahiro Taniguchi: An Illustrated Guide To Artificial Intelligence, pp. 256, Kodansha Ltd.（2020） …………… Youichiro Miyake 535
Ryuichiro Higashinaka: Chatting Skills of AI, pp. 272, KADOKAWA（2021） …………………………………… Youichiro Miyake 536
Article
Cover Comment: Discrete Structures in the Summer Sky ………………………………………………………………Takeshi Sakaki 537