Yanjing Wang (王彦晶)

I am a logician at the department of philosophy of Peking University. Currently, I am a tenured associate professor of logic and the deputy chair of the department and also the deputy director of the PKU Centre for Philosophy and the Future of Humanity. My research mainly focuses on modal logic and its applications in philosophy, theoretical computer science, and AI. In recent years, I have been trying to systematically propose and study logics of know-wh, such as knowing how/why/what/who and so on. The core idea is to  introduce the so-called bundled modalities which pack a quantifier and a modality together. This also leads to some new decidable fragments of first-order modal logic and a general approach to unpacking intuitionistic logic, inquisitive logic, and related non-classical logics as epistemic logics. Here is my CV. You can also find my papers at DBLP, Google Scholar, and Researchgate. My Erdős number is 3.






  • Ph.D. 2010

    Ph.D. in Logic

    CWI & University of Amsterdam

  • MSc. 2006

    Master of Logic

    ILLC, University of Amsterdam

  • B.A. 2004

    Bachelor in Philosophy (Logic)

    Department of Philosophy, Peking University


  • Present2018

    Associate Professor (Tenured), Deputy Chair of the Department

    Department of Philosophy, Peking University

  • 20182012

    Associate Professor

    Department of Philosophy, Peking University

  • 20122010

    Assistant Professor

    Department of Philosophy, Peking University

Kp → p, Kp → KKp, Kp → K¬Kp, K∃xPx → ∃xKPx, K[a]p → [a]Kp, <a>Kp → K[a]p

Research Interests

    • Epistemic Logic
    • First-order Modal Logic
    • Non-normal Modal Logic
    • Dynamic Logic
    • Formal Epistemology
    • Formal Semantics
    • Epistemic Puzzles
    • Formal Verification
    • Knowledge Representation
    • Polyadic Modal Logic
    • Automated Planning
    • Multi-agent System

    Some Projects (not always in terms of research grants)

    • 2020
      Knowing How to Understand Non-classical Logics
      We use epistemic logics of knowing how to unload the meaning behind various non-classical logics.
    • 2019-
      Decidable Fragments of First-order Modal Logic
      Inspired by logics of knowing-wh, we discovered a new family of decidable fragments of first-order logic (NSSF grant 19BZX135).
    • 2013
      Beyond Knowing That: Nonstandard Epistemic Logic of Know-wh
      We propose and study a new family of epistemic logics of know-whether, know-how, know-why, know-who and so on.

    Some questions that I asked (and answered)

    • 2013-
      How to reason about knowing whether/what/how/why?
      See my position paper, and recent papers on know-whether, know-how, know-why, know-what, know-who, and the related course. A general framework was proposed by the TARK 2017 paper.
    • 2017-
      How to handle non-rigid names and de re/de dicto knowledge in a simple way?
      See my AiML 2018 paper with Jeremy Seligman.
    • 2017-
      Are there expressive and decidable fragments of first-oder modal logic which do not restrict the variables and predicates?
      Yes! Inspired by the epistemic logics of know-wh I developed in my “beyond knowing that” project, I discovered the so-called bundled fragments, see my TARK2017 paper and FSTTCS2018 paper with Anantha Padmanabha and Ramanujam.
    • 2014-2015
      How to unify different interpretations of information sets in game theory?
      See my Studies in Logic paper (2015) with Kai Li
    • 2012-2018
      How to do planning using a framework combining advantages of both DEL and ETL?
      See my AiML2012 paper with Yanjun Li and JLC 2017 paper with Yanjun Li and Quan Yu, and the AIJ paper on probabilistic planning with Yanjun Li and Barteld Kooi
    • 2011-2013
      Can we axiomatize Dynamic Epistemic Logics without reductions?
      Yes! We can do it in a general and meaningful way which may sharpen our understanding about the underlying assumptions behind the dynamic epistemic logic. See my Synthese paper (2013) with Qinxiang Cao, and IJCAI paper (2013) with Guillaume Aucher. We used such techniques in various other works on planning and know-how.
    • 2012
      Can we fully formalize the ``hardest puzzle ever`` and look for solutions automatically?
      Yes. See my Minds and Machines paper (2012) with Fenrong Liu. It uses the ideas from my works on protocol verifications with context depedent semantics.
    • 2009-2013
      How to reason about lies and ``true lies``
      See my paper on the logic of lying with Hans van Ditmarsch, Jan van Eijck, and Floor Sietma, and the Synthese paper (2018) on true lies (lies that become true after they are said) with Thomas Agotnes and Hans van Ditmarsch.
    • 2009-2011
      How can actions carry meaning and how can we reason about them?
      I provide a logical framework with a kind of context-dependent semantics where actions carry information based on commonly known protocols. See my PhD thesis (2010), ICLA 2011 paper and the AIJ 2014 paper with Hans van Ditmarsch, Rineke Verbrugge and Sujata Ghosh.
    • 2007-2010
      How to build and check epistemic models in an intuitive and compositional way?
      We design a way of composing models from partial models for each agent. See our JANCL paper (2011) with Jan van Eijck and Floor Sietsma. See my ICLA paper, ICTAC 2008 paper with Francien Dechesne and Simona Orzan and TASE2008 paper with Taolue Chen and Jaco van der Pol for how to make the epistemic model smaller by various methods of abstractions.
    • 2006-2010
      How does epistemic logic matter in security verification?
      See my Synthese paper (2010) with Francien Deschene. When verifying epistemic protocols, whether the adversary knows the protocol matters, see TARK2009 paper and DALT 2010 paper.