structure for 'Formal Logic'    |     alphabetical list of themes    |     unexpand these ideas

4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / e. System K4

[version imposing one condition on accessibility]

1 idea
The system K4 has the 'transitive' condition on its accessibility relation [Fitting/Mendelsohn]
     Full Idea: The system K4 has the 'transitive' condition imposed on its accessibility relation - that is, if a relation holds between worlds 1 and 2 and worlds 2 and 3, it must hold between worlds 1 and 3. The relation carries over.
     From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.8)