Modal logic Nessitation rule

From: translogi <wilemien@xxxxxxxxxxxxxx>
Date: Thu, 30 Aug 2007 12:26:29 -0000

Am I getting confused?

I seem to have lost grips with the nessitation rule

Does it only apply to Theorems/ axioms (valid in all worlds) or also
to premmisses (valid in some worlds)?

If it is only the first what is the fuzz al about?
But also then how aboul modal logics where the rule doesn't hold.
(like Grz)

I am just getting utterly confused here.
Can somebody put me back on line here?

.

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