Combining Texts

All the ideas for 'Conditionals', 'On the Nature of Mathematical Reasoning' and 'Gentzen's Analysis of First-Order Proofs'

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8 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 / 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]

6. Mathematics / A. Nature of Mathematics / 5. The Infinite / d. Actual infinite

15923

Poincaré rejected the actual infinite, claiming definitions gave apparent infinity to finite objects [Poincaré, by Lavine]

10. Modality / B. Possibility / 8. Conditionals / a. Conditionals

13768

Validity can preserve certainty in mathematics, but conditionals about contingents are another matter [Edgington]

10. Modality / B. Possibility / 8. Conditionals / b. Types of conditional

13770

There are many different conditional mental states, and different conditional speech acts [Edgington]

10. Modality / B. Possibility / 8. Conditionals / c. Truth-function conditionals

13764

Are conditionals truth-functional - do the truth values of A and B determine the truth value of 'If A, B'? [Edgington]

13765

'If A,B' must entail ¬(A & ¬B); otherwise we could have A true, B false, and If A,B true, invalidating modus ponens [Edgington]