19 ideas
10757 | Henkin semantics has a second domain of predicates and relations (in upper case) [Rossberg] |
10751 | Second-order logic needs the sets, and its consequence has epistemological problems [Rossberg] |
10759 | There are at least seven possible systems of semantics for second-order logic [Rossberg] |
10753 | Logical consequence is intuitively semantic, and captured by model theory [Rossberg] |
10752 | Γ |- S says S can be deduced from Γ; Γ |= S says a good model for Γ makes S true [Rossberg] |
10754 | In proof-theory, logical form is shown by the logical constants [Rossberg] |
10756 | A model is a domain, and an interpretation assigning objects, predicates, relations etc. [Rossberg] |
10758 | If models of a mathematical theory are all isomorphic, it is 'categorical', with essentially one model [Rossberg] |
10761 | Completeness can always be achieved by cunning model-design [Rossberg] |
10755 | A deductive system is only incomplete with respect to a formal semantics [Rossberg] |
13804 | A property is essential iff the object would not exist if it lacked that property [Forbes,G] |
13805 | Properties are trivially essential if they are not grounded in a thing's specific nature [Forbes,G] |
13808 | A relation is essential to two items if it holds in every world where they exist [Forbes,G] |
13806 | Trivially essential properties are existence, self-identity, and de dicto necessities [Forbes,G] |
13807 | A property is 'extraneously essential' if it is had only because of the properties of other objects [Forbes,G] |
13809 | One might be essentialist about the original bronze from which a statue was made [Forbes,G] |
13810 | The source of de dicto necessity is not concepts, but the actual properties of the thing [Forbes,G] |
13304 | Learned men gain more in one day than others do in a lifetime [Posidonius] |
20820 | Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus] |