Combining Philosophers

Ideas for William S. Jevons, George Engelbretsen and Feferman / Feferman

expand these ideas     |    start again     |     choose another area for these philosophers

display all the ideas for this combination of philosophers

11 ideas

5. Theory of Logic / A. Overview of Logic / 2. History of Logic
18912 Was logic a branch of mathematics, or mathematics a branch of logic? [Engelbretsen]
5. Theory of Logic / E. Structures of Logic / 1. Logical Form
18905 Propositions can be analysed as pairs of terms glued together by predication [Engelbretsen]
18922 Logical syntax is actually close to surface linguistic form [Engelbretsen]
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / c. not
18908 Standard logic only negates sentences, even via negated general terms or predicates [Engelbretsen]
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
10158 A structure is a 'model' when the axioms are true. So which of the structures are models? [Feferman/Feferman]
10162 Tarski and Vaught established the equivalence relations between first-order structures [Feferman/Feferman]
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
10160 Löwenheim-Skolem says if the sentences are countable, so is the model [Feferman/Feferman]
10159 Löwenheim-Skolem Theorem, and Gödel's completeness of first-order logic, the earliest model theory [Feferman/Feferman]
5. Theory of Logic / K. Features of Logics / 4. Completeness
10161 If a sentence holds in every model of a theory, then it is logically derivable from the theory [Feferman/Feferman]
5. Theory of Logic / K. Features of Logics / 7. Decidability
10156 'Recursion theory' concerns what can be solved by computing machines [Feferman/Feferman]
10155 Both Principia Mathematica and Peano Arithmetic are undecidable [Feferman/Feferman]