Combining Texts

All the ideas for 'reports', 'An Introduction to Modal Logic' and 'Letters to Wagner'

expand these ideas     |    start again     |     specify just one area for these texts

---

6 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]

10. Modality / A. Necessity / 8. Transcendental Necessity

3016	Even the gods cannot strive against necessity [Pittacus, by Diog. Laertius]

26. Natural Theory / A. Speculations on Nature / 7. Later Matter Theories / a. Early Modern matter

19436

Bare or primary matter is passive; it is clothed or secondary matter which contains action [Leibniz]