Combining Texts

All the ideas for 'Natural Science (lost)', 'Principles of Theoretical Logic' and 'works'

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

---

4 ideas

4. Formal Logic / C. Predicate Calculus PC / 1. Predicate Calculus PC

17750

The first clear proof of the consistency of the first order predicate logic was in 1928 [Hilbert/Ackermann, by Walicki]

6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / a. Axioms for numbers

3338	Numbers have been defined in terms of 'successors' to the concept of 'zero' [Peano, by Blackburn]

6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / d. Peano arithmetic

5897	0 is a non-successor number, all successors are numbers, successors can't duplicate, if P(n) and P(n+1) then P(all-n) [Peano, by Flew]

7. Existence / A. Nature of Existence / 6. Criterion for Existence

527	Everything exists which anyone perceives [Metrodorus of Chios]