Combining Texts

All the ideas for '', 'A Completeness Theorem in Modal Logic' and 'A Realistic Theory of Categories'

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9 ideas

4. Formal Logic / D. Modal Logic ML / 1. Modal Logic

10163

Propositional modal logic has been proved to be complete [Kripke, by Feferman/Feferman]

4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / a. Systems of modal logic

10760

With possible worlds, S4 and S5 are sound and complete, but S1-S3 are not even sound [Kripke, by Rossberg]

4. Formal Logic / D. Modal Logic ML / 7. Barcan Formula

16189

The variable domain approach to quantified modal logic invalidates the Barcan Formula [Kripke, by Simchen]

15132

The Barcan formulas fail in models with varying domains [Kripke, by Williamson]

5. Theory of Logic / A. Overview of Logic / 1. Overview of Logic

11211

If a sound conclusion comes from two errors that cancel out, the path of the argument must matter [Rumfitt]

5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / a. Logical connectives

11210

Standardly 'and' and 'but' are held to have the same sense by having the same truth table [Rumfitt]

11212

The sense of a connective comes from primitively obvious rules of inference [Rumfitt]

7. Existence / E. Categories / 3. Proposed Categories

13120

Chisholm divides things into contingent and necessary, and then individuals, states and non-states [Chisholm, by Westerhoff]

19. Language / F. Communication / 3. Denial

11214

We learn 'not' along with affirmation, by learning to either affirm or deny a sentence [Rumfitt]