Some Truths Are Best Left Unsaid

نویسندگان

  • Philippe Balbiani
  • Hans van Ditmarsch
  • Andreas Herzig
  • Tiago De Lima
چکیده

We study the formal properties of extensions of the basic public announcement logic by standard modal axioms such as D, T, 2, 4, and 5. We show that some of them fail to be conservative extensions of the underlying modal logic. This leads us to propose new truth conditions for announcements that better suit these extensions. The corresponding reduction axioms postulate the suitability of the updated model to the underlying logic. We show that if the fact can be expressed that the frame of an updated model is in the class of frames of the underlying modal logic, then the public announcement extension is axiomatisable. This is the case for, for example, K, KT, S4, and S4.3. We also show that such a formula does not exist for several logics whose frame condition involves existential quantification. This is the case for, for example, S4.2.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Comedy, Context and Unsaid Meaning: A Case Study in Conversational Implicature

Pragmatics moves away from the word level and sentence level study of language towards the study of language in real-world context and at discourse level whereby two or more participants take part in conversation. There are moments when the speaker explicitly says something but the listener may have other interpretations and inferences from their statements. The aim of this study was to demonst...

متن کامل

Lynch ’ s Metaphysical Pluralism

Pluralism, according to Michael P. Lynch, is the thesis that there are or can be more than one true story of the world; there can be incompatible but equally acceptable accounts of some subject matter.’ The opposite view, absolutism, states that there can be only one true story about how the world is. In our ordinary lives both theses have intuitive pull. Most of us are ready to say that there ...

متن کامل

A Lesson for Electrocardiography ? Update

Update placed by new imaging methods in many applications. And in some applications, ECG is even considered obsolete, eg, in the diagnostics of left ventricular hypertrophy (LVH). The rational way to increase the interest of cardiolo-gists, to attract young scientists, and to increase the value of ECG, is to analyze and consequently to reduce its limitations. This means, first, to reevaluate th...

متن کامل

A Defense of Contingent Logical Truths∗

A formula is a contingent logical truth when it is true in every model M but, for some model M , false at some world of M . We argue that there are such truths, given the logic of actuality. Our argument turns on defending Tarski’s definition of truth and logical truth, extended so as to apply to modal languages with an actuality operator. We argue that this extension is the philosophically pro...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2012