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Single Idea 9745

[filed under theme 4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / f. System B ]

Full Idea

The system B has the 'reflexive' and 'symmetric' conditions imposed on its accessibility relation - that is, every world must be accessible to itself, and any relation between worlds must be mutual.

Gist of Idea

The system B has the 'reflexive' and 'symmetric' conditions on its accessibility relation

Source

M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.8)

Book Ref

Fitting,M/Mendelsohn,R: 'First-Order Modal Logic' [Synthese 1998], p.19

The 5 ideas with the same theme [version imposing two conditions on accessibility]:

14667 System B has not been justified as fallacy-free for reasoning on what might have been [Salmon,N]
14668 In B it seems logically possible to have both p true and p is necessarily possibly false [Salmon,N]
14692 System B implies that possibly-being-realized is an essential property of the world [Salmon,N]
9745 The system B has the 'reflexive' and 'symmetric' conditions on its accessibility relation [Fitting/Mendelsohn]
13711 System B introduces iterated modalities [Sider]