Combining Texts

All the ideas for 'fragments/reports', 'The Concept of Logical Consequence' and 'Gentzen's Analysis of First-Order Proofs'

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7 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

14180

Etchemendy says fix the situation and vary the interpretation, or fix interpretations with varying situations [Etchemendy, by Read]

14181

Validity is where either the situation or the interpretation blocks true premises and false conclusion [Etchemendy, by Read]

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]

26. Natural Theory / A. Speculations on Nature / 5. Infinite in Nature

1748	Archelaus was the first person to say that the universe is boundless [Archelaus, by Diog. Laertius]

27. Natural Reality / G. Biology / 3. Evolution

5989	Archelaus said life began in a primeval slime [Archelaus, by Schofield]