37 ideas
10476 | The idea that groups of concepts could be 'implicitly defined' was abandoned [Hodges,W] |
10282 | Logic is the study of sound argument, or of certain artificial languages (or applying the latter to the former) [Hodges,W] |
10478 | Since first-order languages are complete, |= and |- have the same meaning [Hodges,W] |
10477 | |= in model-theory means 'logical consequence' - it holds in all models [Hodges,W] |
15105 | F(x) walked into a bar. The barman said.. [Sommers,W] |
10283 | A formula needs an 'interpretation' of its constants, and a 'valuation' of its variables [Hodges,W] |
10284 | There are three different standard presentations of semantics [Hodges,W] |
10285 | I |= φ means that the formula φ is true in the interpretation I [Hodges,W] |
10474 | |= should be read as 'is a model for' or 'satisfies' [Hodges,W] |
10475 | A 'structure' is an interpretation specifying objects and classes of quantification [Hodges,W] |
10473 | Model theory studies formal or natural language-interpretation using set-theory [Hodges,W] |
10481 | Models in model theory are structures, not sets of descriptions [Hodges,W] |
10289 | Up Löwenheim-Skolem: if infinite models, then arbitrarily large models [Hodges,W] |
10288 | Down Löwenheim-Skolem: if a countable language has a consistent theory, that has a countable model [Hodges,W] |
10287 | If a first-order theory entails a sentence, there is a finite subset of the theory which entails it [Hodges,W] |
10480 | First-order logic can't discriminate between one infinite cardinal and another [Hodges,W] |
10286 | A 'set' is a mathematically well-behaved class [Hodges,W] |
12408 | Sartre to Waitress: Coffee with no cream, please... [Sommers,W] |
12397 | Said Plato: 'The things that we feel... [Sommers,W] |
12407 | Barman to Descartes: Would you like another drink?... [Sommers,W] |
12399 | There was a young student called Fred... [Sommers,W] |
20963 | A philosopher and his wife are out for a drive... [Sommers,W] |
12409 | The philosopher Berkeley once said.. [Sommers,W] |
12404 | Dear Sir, Your astonishment's odd.... [Sommers,W] |
12403 | There once was a man who said: 'God... [Sommers,W] |
12402 | ..But if he's a student of Berkeley... [Sommers,W] |
14694 | "My dog's got synaesthesia." How does he smell? ..... [Sommers,W] |
12401 | A toper who spies in the distance... [Sommers,W] |
12410 | There once was a man who said 'Damn!... [Sommers,W] |
9392 | How do behaviourists greet each other? [Sommers,W] |
12405 | 'If you're aristocratic,' said Nietzsche... [Sommers,W] |
9391 | Why do anarchists drink herbal tea? [Sommers,W] |
12400 | Cries the maid: 'You must marry me Hume!'... [Sommers,W] |
16527 | Causation - we all thought we knew it/ Till Hume came along and saw through it/…. [Sommers,W] |
17592 | The barman called 'Time!', and Augustine said..... [Sommers,W] |
15208 | The past, present and future walked into a bar.... [Sommers,W] |
1558 | Clearly the gods ignore human affairs, or they would have given us justice [Thrasymachus] |