On the relationship between tetravalent modal algebras, symmetric Boolean algebras and modal algebras for S5
(Marcelo E. Coniglio, Martín Figallo)
Update: the final version of this paper has been published as:
M.E. Coniglio; M. Figallo. On a four-valued modal logic with deductive implication. Bulletin of the Section of Logic 43, n. 1/2: 1-18, 2014.