In this paper, we examine weak logics similar to S0.5[\Box Φ], where Φ ⊆ S0.5. We also examine their versions (one of which is S0.5rte[\Box Φ]) that are closed under the replacement of tautological equivalents (rte). We ...

In the present paper we examine very weak modal logics C1, D1, E1, S0.5◦, S0.5◦+(D), S0.5 and some of their versions which are closed under replacement of tautological equivalents (rte-versions). We give semantics for these ...