Take the distribution axiom, DA, of a modal logic to be:
$\Box(A\to B)\to (\Box A \to \Box B).$
As there are distribution-free modal logics which do not have DA:
What does DA correspond to in frames that validate it?
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- 4$\begingroup$ What kind of frames do you have in mind? All Kripke frames validate this axiom, obviously. $\endgroup$Emil Jeřábek– Emil Jeřábek2025-04-11 16:16:15 +00:00Commented Apr 11 at 16:16
- $\begingroup$ @EmilJeřábek Aha - yes! So distribution-free modal logics do not have a Kripke model. $\endgroup$Frode Alfson Bjørdal– Frode Alfson Bjørdal2025-04-11 16:25:20 +00:00Commented Apr 11 at 16:25
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