Combining Texts

All the ideas for 'fragments/reports', 'An Introduction to Modal Logic' and 'Relations'

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10 ideas

4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / b. Terminology of PL
9540 A 'value-assignment' (V) is when to each variable in the set V assigns either the value 1 or the value 0 [Hughes/Cresswell]
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / d. Basic theorems of PL
9541 The Law of Transposition says (P→Q) → (¬Q→¬P) [Hughes/Cresswell]
4. Formal Logic / B. Propositional Logic PL / 4. Soundness of PL
9543 The rules preserve validity from the axioms, so no thesis negates any other thesis [Hughes/Cresswell]
5. Theory of Logic / K. Features of Logics / 4. Completeness
9544 A system is 'weakly' complete if all wffs are derivable, and 'strongly' if theses are maximised [Hughes/Cresswell]
7. Existence / A. Nature of Existence / 3. Being / d. Non-being
18933 Not-Being obviously doesn't exist, and the five modes of Being are all impossible [Gorgias, by Diog. Laertius]
8. Modes of Existence / A. Relations / 1. Nature of Relations
21354 It may be that internal relations like proportion exist, because we directly perceive it [MacBride]
8. Modes of Existence / A. Relations / 2. Internal Relations
21353 Internal relations are fixed by existences, or characters, or supervenience on characters [MacBride]
8. Modes of Existence / A. Relations / 4. Formal Relations / a. Types of relation
21352 'Multigrade' relations are those lacking a fixed number of relata [MacBride]
19. Language / F. Communication / 1. Rhetoric
5864 Destroy seriousness with laughter, and laughter with seriousness [Gorgias]
9866 Gorgias says rhetoric is the best of arts, because it enslaves without using force [Gorgias, by Plato]