the logical study of such philosophical concepts as necessity, possibility, contingency, etc
2.
the logical study of concepts whose formal properties resemble certain moral, epistemological, and psychological concepts
See also alethic, deontic, epistemic, doxastic
3.
any formal system capable of being interpreted as a model for the behaviour of such concepts
Examples of 'modal logic' in a sentence
modal logic
Here we examine proof systems for modal logic with fixpoints.
Colin Stirling 2013, 'A Proof System with Names for Modal Mu-calculus', Electronic Proceedings in Theoretical Computer Sciencehttp://arxiv.org/pdf/1309.5129v1. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
It employs an embedding of quantified modal logic in classical higher-order logic.
Christoph Benzmüller, Maximilian Claus, Nik Sultana 2015, 'Systematic Verification of the Modal Logic Cube in Isabelle/HOL', Electronic Proceedings in Theoretical Computer Sciencehttp://arxiv.org/pdf/1507.08717v1. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
We have previously studied its logical characterization by means of the covariant-contravariant modal logic.
Miguel Palomino, Anna Ingólfsdóttir, David de Frutos-Escrig, Ignacio Fábregas, LucaAceto 2011, 'Graphical representation of covariant-contravariant modal formulae', Electronic Proceedings in Theoretical Computer Sciencehttp://arxiv.org/pdf/1108.4464v1. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
We introduce now for the first time the neutrosophic modal logic.
Florentin Smarandache 2017, 'Neutrosophic Modal Logic', Neutrosophic Sets and Systemshttp://fs.gallup.unm.edu/NSS/NeutrosophicModalLogic.pdf. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)