13 ideas
13201 | ∈ says the whole set is in the other; ⊆ says the members of the subset are in the other [Enderton] |
13204 | The 'ordered pair' <x,y> is defined to be {{x}, {x,y}} [Enderton] |
13206 | A 'linear or total ordering' must be transitive and satisfy trichotomy [Enderton] |
13200 | Note that {Φ} =/= Φ, because Φ ∈ {Φ} but Φ ∉ Φ [Enderton] |
13199 | The empty set may look pointless, but many sets can be constructed from it [Enderton] |
13203 | The singleton is defined using the pairing axiom (as {x,x}) [Enderton] |
13202 | Fraenkel added Replacement, to give a theory of ordinal numbers [Enderton] |
13205 | We can only define functions if Choice tells us which items are involved [Enderton] |
14633 | How do we tell a table's being contingently plastic from its being essentially plastic? [Jackson] |
14635 | An x is essentially F if it is F in every possible world in which it appears [Jackson] |
14632 | Quine may have conflated de re and de dicto essentialism, but there is a real epistemological problem [Jackson] |
14631 | How can you show the necessity of an a posteriori necessity, if it might turn out to be false? [Jackson] |
8130 | Qualities of experience are just representational aspects of experience ('Representationalism') [Harman, by Burge] |