17 ideas
| 13201 | ∈ says the whole set is in the other; ⊆ says the members of the subset are in the other [Enderton] |
| 13206 | A 'linear or total ordering' must be transitive and satisfy trichotomy [Enderton] |
| 13204 | The 'ordered pair' <x,y> is defined to be {{x}, {x,y}} [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] |
| 8228 | Being is revealed at the point between waking and sleep [Anon (Cent)] |
| 22200 | If you eliminate the impossible, the truth will remain, even if it is weird [Conan Doyle] |
| 8232 | Neglect your self, and feel the consciousness of each other being [Anon (Cent)] |
| 8230 | Just as you have the impulse to do something, stop [Anon (Cent)] |
| 8234 | Bondage and liberation are relative terms, which only frighten those already terrified of the universe [Anon (Cent)] |
| 8227 | Feel your whole body saturated with cosmic essence [Anon (Cent)] |
| 8229 | The serenity in blue sky beyond clouds [Anon (Cent)] |
| 8231 | Abandon attachment to body, and feel the joy of being everywhere [Anon (Cent)] |
| 8233 | Imagine fire burning up your whole body, but not you [Anon (Cent)] |