19 ideas
13560 | A wise man is not subservient to anything [Seneca] |
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] |
13558 | The supreme good is harmony of spirit [Seneca] |
13559 | I seek virtue, because it is its own reward [Seneca] |
13561 | Virtue is always moderate, so excess need not be feared [Seneca] |
13562 | It is shameful to not even recognise your own slaves [Seneca] |
13564 | There is far more scope for virtue if you are wealthy; poverty only allows endurance [Seneca] |
13563 | Why does your wife wear in her ears the income of a wealthy house? [Seneca] |
13565 | If wealth was a good, it would make men good [Seneca] |
13557 | Unfortunately the majority do not tend to favour what is best [Seneca] |
13304 | Learned men gain more in one day than others do in a lifetime [Posidonius] |
20820 | Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus] |