16 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] |
15567 | Some events involve no change; they must, because causal histories involve unchanges [Lewis] |
15561 | The events that suit semantics may not be the events that suit causation [Lewis] |
15565 | Events have inbuilt essences, as necessary conditions for their occurrence [Lewis] |
15566 | Events are classes, and so there is a mereology of their parts [Lewis] |
15564 | An event is a property of a unique space-time region [Lewis] |
15563 | Properties are very abundant (unlike universals), and are used for semantics and higher-order variables [Lewis] |
7903 | The six perfections are giving, morality, patience, vigour, meditation, and wisdom [Nagarjuna] |
15562 | Causation is a general relation derived from instances of causal dependence [Lewis] |