[BdRV01] Patrick Blackburn, Maarten de Rijke, Yde Venema.
Modal Logic.
Number 53.
Cambridge University Press, 2001.
URL: https://www.mlbook.org. [1][2]
[DB18] Christian Doczkal, Joachim Bard.
Completeness and decidability of converse PDL in the constructive type theory of Coq.
In CPP 2018, 42–52. Jan 2018.
See also https://github.com/coq-community/comp-dec-modal.
URL: https://doi.org/10.1145/3167088. [1]