29 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] |
10900 | Logically true sentences are true in all structures [Zalabardo] |
10895 | 'Logically true' (|= φ) is true for every truth-assignment [Zalabardo] |
10901 | Some formulas are 'satisfiable' if there is a structure and interpretation that makes them true [Zalabardo] |
10894 | A sentence-set is 'satisfiable' if at least one truth-assignment makes them all 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] |
6649 | Chomsky now says concepts are basically innate, as well as syntax [Chomsky, by Lowe] |
8239 | If the King likes music then there is hope for the state [Mengzi (Mencius)] |
23398 | Human nature is naturally compassionate and good (as a 'sprout'), but people may not be good [Mengzi (Mencius), by Norden] |
23400 | Righteousness is extending the unthinkable, to reveal what must be done [Mengzi (Mencius)] |
23399 | Each correct feeling relies on an underlying virtue [Mengzi (Mencius)] |
8235 | Should a coward who ran fifty paces from a battle laugh at another who ran a hundred? [Mengzi (Mencius)] |
8240 | A true king shares his pleasure with the people [Mengzi (Mencius)] |
8237 | Extend the treatment of the old and young in your family to the rest of society [Mengzi (Mencius)] |
8241 | Only put someone to death if the whole population believes it is deserved [Mengzi (Mencius)] |
8238 | Seeking peace through war is like looking for fish up a tree [Mengzi (Mencius)] |
8236 | Avoid the animals you are going to eat, as it is hard once you have got to know them [Mengzi (Mencius)] |