29 ideas
1564 | True and false statements can use exactly the same words [Anon (Diss)] |
9470 | Modal logic is not an extensional language [Parsons,C] |
13030 | Extensionality: ∀x ∀y (∀z (z ∈ x ↔ z ∈ y) → x = y) [Kunen] |
13032 | Pairing: ∀x ∀y ∃z (x ∈ z ∧ y ∈ z) [Kunen] |
13033 | Union: ∀F ∃A ∀Y ∀x (x ∈ Y ∧ Y ∈ F → x ∈ A) [Kunen] |
13037 | Infinity: ∃x (0 ∈ x ∧ ∀y ∈ x (S(y) ∈ x) [Kunen] |
13038 | Power Set: ∀x ∃y ∀z(z ⊂ x → z ∈ y) [Kunen] |
13034 | Replacement: ∀x∈A ∃!y φ(x,y) → ∃Y ∀X∈A ∃y∈Y φ(x,y) [Kunen] |
13039 | Foundation:∀x(∃y(y∈x) → ∃y(y∈x ∧ ¬∃z(z∈x ∧ z∈y))) [Kunen] |
13036 | Choice: ∀A ∃R (R well-orders A) [Kunen] |
13418 | The old problems with the axiom of choice are probably better ascribed to the law of excluded middle [Parsons,C] |
13029 | Set Existence: ∃x (x = x) [Kunen] |
13031 | Comprehension: ∃y ∀x (x ∈ y ↔ x ∈ z ∧ φ) [Kunen] |
13040 | Constructibility: V = L (all sets are constructible) [Kunen] |
9469 | Substitutional existential quantifier may explain the existence of linguistic entities [Parsons,C] |
9468 | On the substitutional interpretation, '(∃x) Fx' is true iff a closed term 't' makes Ft true [Parsons,C] |
17447 | Parsons says counting is tagging as first, second, third..., and converting the last to a cardinal [Parsons,C, by Heck] |
18201 | General principles can be obvious in mathematics, but bold speculations in empirical science [Parsons,C] |
13419 | If functions are transfinite objects, finitists can have no conception of them [Parsons,C] |
13417 | If a mathematical structure is rejected from a physical theory, it retains its mathematical status [Parsons,C] |
18465 | An 'equivalence' relation is one which is reflexive, symmetric and transitive [Kunen] |
1560 | Lydians prostitute their daughters to raise a dowery, but no Greek would marry such a girl [Anon (Diss)] |
1559 | Thracians think tattooing adds to a girl's beauty, but elsewhere it is a punishment [Anon (Diss)] |
1561 | Anything can be acceptable in some circumstances and unacceptable in others [Anon (Diss)] |
1567 | How could someone who knows everything fail to act correctly? [Anon (Diss)] |
1563 | Every apparent crime can be right in certain circumstances [Anon (Diss), by PG] |
1562 | It is right to lie to someone, to get them to take medicine they are reluctant to take [Anon (Diss)] |
1566 | The first priority in elections is to vote for people who support democracy [Anon (Diss)] |
1565 | We learn language, and we don't know who teaches us it [Anon (Diss)] |