41 ideas
17749 | Post proved the consistency of propositional logic in 1921 [Walicki] |
17765 | Propositional language can only relate statements as the same or as different [Walicki] |
17764 | Boolean connectives are interpreted as functions on the set {1,0} [Walicki] |
17752 | The empty set is useful for defining sets by properties, when the members are not yet known [Walicki] |
17753 | The empty set avoids having to take special precautions in case members vanish [Walicki] |
17759 | Ordinals play the central role in set theory, providing the model of well-ordering [Walicki] |
17741 | To determine the patterns in logic, one must identify its 'building blocks' [Walicki] |
15105 | F(x) walked into a bar. The barman said.. [Sommers,W] |
17747 | A 'model' of a theory specifies interpreting a language in a domain to make all theorems true [Walicki] |
17748 | The L-S Theorem says no theory (even of reals) says more than a natural number theory [Walicki] |
17761 | A compact axiomatisation makes it possible to understand a field as a whole [Walicki] |
17763 | Axiomatic systems are purely syntactic, and do not presuppose any interpretation [Walicki] |
17758 | Ordinals are transitive sets of transitive sets; or transitive sets totally ordered by inclusion [Walicki] |
17755 | Ordinals are the empty set, union with the singleton, and any arbitrary union of ordinals [Walicki] |
17756 | The union of finite ordinals is the first 'limit ordinal'; 2ω is the second... [Walicki] |
17760 | Two infinite ordinals can represent a single infinite cardinal [Walicki] |
17757 | Members of ordinals are ordinals, and also subsets of ordinals [Walicki] |
17762 | In non-Euclidean geometry, all Euclidean theorems are valid that avoid the fifth postulate [Walicki] |
17754 | Inductive proof depends on the choice of the ordering [Walicki] |
12408 | Sartre to Waitress: Coffee with no cream, please... [Sommers,W] |
12397 | Said Plato: 'The things that we feel... [Sommers,W] |
17742 | Scotus based modality on semantic consistency, instead of on what the future could allow [Walicki] |
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] |
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] |
12409 | The philosopher Berkeley once said.. [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] |
1748 | Archelaus was the first person to say that the universe is boundless [Archelaus, by Diog. Laertius] |
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] |
5989 | Archelaus said life began in a primeval slime [Archelaus, by Schofield] |