Combining Texts

All the ideas for 'reports', 'The Theory of Logical Types' and 'Set Theory and related topics (2nd ed)'

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7 ideas

4. Formal Logic / F. Set Theory ST / 3. Types of Set / e. Equivalence classes
8920 Equivalence relations are reflexive, symmetric and transitive, and classify similar objects [Lipschutz]
5. Theory of Logic / E. Structures of Logic / 5. Functions in Logic
21566 'Propositional functions' are ambiguous until the variable is given a value [Russell]
5. Theory of Logic / L. Paradox / 6. Paradoxes in Language / a. The Liar paradox
21567 'All judgements made by Epimenedes are true' needs the judgements to be of the same type [Russell]
6. Mathematics / C. Sources of Mathematics / 6. Logicism / b. Type theory
23457 Type theory cannot identify features across levels (because such predicates break the rules) [Morris,M on Russell]
21556 Classes are defined by propositional functions, and functions are typed, with an axiom of reducibility [Russell, by Lackey]
6. Mathematics / C. Sources of Mathematics / 10. Constructivism / d. Predicativism
21568 A one-variable function is only 'predicative' if it is one order above its arguments [Russell]
10. Modality / A. Necessity / 8. Transcendental Necessity
3016 Even the gods cannot strive against necessity [Pittacus, by Diog. Laertius]