We are glad to announce the winner of the Universal Logic Prize for China 2025 https://www.uni-log.org/logic-prize-china-2025 China is a big country and there were 14 members in the jury of the prize, promoting interaction between people working in all aspects of logic in the country.
Zhu Rui, Datang Hydropower Plant, Chengguan Town, Shaanxi Province, China Title of the paper: Arbitrary Announcements in Social Networks: A Finitary Proof System Abstract: Social Announcement Logic (SAL) is a framework for reasoning about belief diffusion in social networks, where information propagates locally based on an underlying follower structure. A key challenge in this area is to logically characterize what agents can achieve through communication, a problem often addressed using powerful but complex arbitrary announcement operators. Pre- vious work on SAL with such operators resulted in infinitary axiomatizations, leaving the question of a finitary system open. This paper solves this open problem by presenting the first finitary, sound, and weakly complete axiomatization for a Social Announcement Logic with an arbitrary sincere announcement operator. Our central technical innovation is a novel, two-stage model transformation technique used to prove the soundness of the crucial discharge rule for arbitrary announcements. This method avoids the complex necessity-form techniques common in the literature on Arbitrary Pub- lic Announcement Logic, resulting in a more direct, Henkin-style completeness proof. Furthermore, we analyze the expressive power of our logic, showing that the fundamental follower relation becomes definable under the natural semantic constraint of weak coherence. We provide a sound and complete axiomatization for this important class of coherent models, highlighting the power of the free announcement operator introduced in our system. This work provides a robust and computable proof-theoretic foundation for reasoning about belief dynamics in social networks. This paper will be published in the journal Logica Universalis and presented at the 8th UNILOG in Cusco at the 3rd World Logic Prizes Contest https://sites.google.com/view/unilog2025/logic-prizes Jean-Yves Beziau, Federal University of Rio de Janeiro https://philpeople.org/profiles/jean-yves-beziau Project A PRIZE OF LOGIC IN EVERY COUNTRY ! https://www.uni-log.org/logic-prize-world -- LOGICA-L Lista acadêmica brasileira dos profissionais e estudantes da área de Lógica <[email protected]> --- Você está recebendo esta mensagem porque se inscreveu no grupo "LOGICA-L" dos Grupos do Google. Para cancelar inscrição nesse grupo e parar de receber e-mails dele, envie um e-mail para [email protected]. Para ver esta conversa, acesse https://groups.google.com/a/dimap.ufrn.br/d/msgid/logica-l/CAF2zFLD59VkkGdeefDd1YEaCB6WHHnYhqXtSn_Ng%3Dy8VhRFGOg%40mail.gmail.com.
