18 ideas
10751 | Second-order logic needs the sets, and its consequence has epistemological problems [Rossberg] |
10757 | Henkin semantics has a second domain of predicates and relations (in upper case) [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] |
11976 | Aristotelian essentialism says essences are not relative to specification [Lewis] |
11978 | Causal necessities hold in all worlds compatible with the laws of nature [Lewis] |
11979 | It doesn't take the whole of a possible Humphrey to win the election [Lewis] |
16994 | Counterpart theory is bizarre, as no one cares what happens to a mere counterpart [Kripke on Lewis] |
11974 | Counterparts are not the original thing, but resemble it more than other things do [Lewis] |
11975 | If the closest resembler to you is in fact quite unlike you, then you have no counterpart [Lewis] |
11977 | Essential attributes are those shared with all the counterparts [Lewis] |
1590 | The just man does not harm his enemies, but benefits everyone [Plato] |