Combining Texts

All the ideas for 'Through the Looking Glass', 'The Logical Syntax of Language' and 'Gentzen's Analysis of First-Order Proofs'

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

---

6 ideas

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

13831

Logic is based on transitions between sentences [Prawitz]

5. Theory of Logic / B. Logical Consequence / 1. Logical Consequence

13342

Carnap defined consequence by contradiction, but this is unintuitive and changes with substitution [Tarski on Carnap]

5. Theory of Logic / C. Ontology of Logic / 4. Logic by Convention

13251

Each person is free to build their own logic, just by specifying a syntax [Carnap]

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

13825

Natural deduction introduction rules may represent 'definitions' of logical connectives [Prawitz]

5. Theory of Logic / H. Proof Systems / 4. Natural Deduction

13823

In natural deduction, inferences are atomic steps involving just one logical constant [Prawitz]

7. Existence / A. Nature of Existence / 3. Being / e. Being and nothing

21982

I only wish I had such eyes as to see Nobody! It's as much as I can do to see real people. [Carroll,L]