Combining Texts

All the ideas for 'Truth', 'First-order Logic, 2nd-order, Completeness' and 'Semantic Necessity'

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20 ideas

3. Truth / F. Semantic Truth / 1. Tarski's Truth / a. Tarski's truth definition
Truth rests on Elimination ('A' is true → A) and Introduction (A → 'A' is true) [Gupta]
3. Truth / F. Semantic Truth / 2. Semantic Truth
A weakened classical language can contain its own truth predicate [Gupta]
5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
Second-order logic needs the sets, and its consequence has epistemological problems [Rossberg]
Henkin semantics has a second domain of predicates and relations (in upper case) [Rossberg]
There are at least seven possible systems of semantics for second-order logic [Rossberg]
5. Theory of Logic / B. Logical Consequence / 2. Types of Consequence
Logical consequence is intuitively semantic, and captured by model theory [Rossberg]
5. Theory of Logic / B. Logical Consequence / 3. Deductive Consequence |-
Γ |- S says S can be deduced from Γ; Γ |= S says a good model for Γ makes S true [Rossberg]
5. Theory of Logic / E. Structures of Logic / 1. Logical Form
In proof-theory, logical form is shown by the logical constants [Rossberg]
5. Theory of Logic / E. Structures of Logic / 8. Theories in Logic
Theories in logic are sentences closed under consequence, but in truth discussions theories have axioms [Fine,K]
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
A model is a domain, and an interpretation assigning objects, predicates, relations etc. [Rossberg]
5. Theory of Logic / J. Model Theory in Logic / 2. Isomorphisms
If models of a mathematical theory are all isomorphic, it is 'categorical', with essentially one model [Rossberg]
5. Theory of Logic / K. Features of Logics / 4. Completeness
Completeness can always be achieved by cunning model-design [Rossberg]
5. Theory of Logic / K. Features of Logics / 5. Incompleteness
A deductive system is only incomplete with respect to a formal semantics [Rossberg]
5. Theory of Logic / L. Paradox / 6. Paradoxes in Language / a. The Liar paradox
The Liar reappears, even if one insists on propositions instead of sentences [Gupta]
Strengthened Liar: either this sentence is neither-true-nor-false, or it is not true [Gupta]
10. Modality / C. Sources of Modality / 1. Sources of Necessity
The role of semantic necessity in semantics is like metaphysical necessity in metaphysics [Fine,K, by Hale/Hoffmann,A]
19. Language / C. Assigning Meanings / 2. Semantics
Semantics is either an assignment of semantic values, or a theory of truth [Fine,K]
Semantics is a body of semantic requirements, not semantic truths or assigned values [Fine,K]
19. Language / C. Assigning Meanings / 7. Extensional Semantics
Referential semantics (unlike Fregeanism) allows objects themselves in to semantic requirements [Fine,K]
19. Language / E. Analyticity / 4. Analytic/Synthetic Critique
The Quinean doubt: are semantics and facts separate, and do analytic sentences have no factual part? [Fine,K]