35 ideas
10888 | Sets can be defined by 'enumeration', or by 'abstraction' (based on a property) [Zalabardo] |
10889 | The 'Cartesian Product' of two sets relates them by pairing every element with every element [Zalabardo] |
10890 | A 'partial ordering' is reflexive, antisymmetric and transitive [Zalabardo] |
10886 | Determinacy: an object is either in a set, or it isn't [Zalabardo] |
10887 | Specification: Determinate totals of objects always make a set [Zalabardo] |
10897 | A first-order 'sentence' is a formula with no free variables [Zalabardo] |
10893 | Γ |= φ for sentences if φ is true when all of Γ is true [Zalabardo] |
10899 | Γ |= φ if φ is true when all of Γ is true, for all structures and interpretations [Zalabardo] |
10896 | Propositional logic just needs ¬, and one of ∧, ∨ and → [Zalabardo] |
10898 | The semantics shows how truth values depend on instantiations of properties and relations [Zalabardo] |
10902 | We can do semantics by looking at given propositions, or by building new ones [Zalabardo] |
10892 | We make a truth assignment to T and F, which may be true and false, but merely differ from one another [Zalabardo] |
10895 | 'Logically true' (|= φ) is true for every truth-assignment [Zalabardo] |
10900 | Logically true sentences are true in all structures [Zalabardo] |
10894 | A sentence-set is 'satisfiable' if at least one truth-assignment makes them all true [Zalabardo] |
10901 | Some formulas are 'satisfiable' if there is a structure and interpretation that makes them true [Zalabardo] |
10903 | A structure models a sentence if it is true in the model, and a set of sentences if they are all true in the model [Zalabardo] |
10891 | If a set is defined by induction, then proof by induction can be applied to it [Zalabardo] |
20339 | Classes rarely share properties with their members - unlike universals and types [Wollheim] |
7295 | Maybe induction is only reliable IF reality is stable [Mitchell,A] |
20338 | We often treat a type as if it were a sort of token [Wollheim] |
20342 | Interpretation is performance for some arts, and critical for all arts [Wollheim] |
20343 | A love of nature must precede a love of art [Wollheim] |
20348 | A criterion of identity for works of art would be easier than a definition [Wollheim] |
20347 | If beauty needs organisation, then totally simple things can't be beautiful [Wollheim] |
20345 | Some say art must have verbalisable expression, and others say the opposite! [Wollheim] |
20331 | It is claimed that the expressive properties of artworks are non-physical [Wollheim] |
20336 | Style can't be seen directly within a work, but appreciation needs a grasp of style [Wollheim] |
20337 | The traditional view is that knowledge of its genre to essential to appreciating literature [Wollheim] |
20333 | If artworks are not physical objects, they are either ideal entities, or collections of phenomena [Wollheim] |
20334 | The ideal theory says art is an intuition, shaped by a particular process, and presented in public [Wollheim] |
20335 | The ideal theory of art neglects both the audience and the medium employed [Wollheim] |
20340 | A musical performance has virtually the same features as the piece of music [Wollheim] |
20341 | An interpretation adds further properties to the generic piece of music [Wollheim] |
20332 | A drawing only represents Napoleon if the artist intended it to [Wollheim] |