Combining Texts

All the ideas for 'Set Theory', 'When Does a Life Begin?' and 'fragments/reports'

expand these ideas     |    start again     |     specify just one area for these texts


18 ideas

4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / b. Axiom of Extensionality I
Extensionality: ∀x ∀y (∀z (z ∈ x ↔ z ∈ y) → x = y) [Kunen]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / c. Axiom of Pairing II
Pairing: ∀x ∀y ∃z (x ∈ z ∧ y ∈ z) [Kunen]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / d. Axiom of Unions III
Union: ∀F ∃A ∀Y ∀x (x ∈ Y ∧ Y ∈ F → x ∈ A) [Kunen]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / f. Axiom of Infinity V
Infinity: ∃x (0 ∈ x ∧ ∀y ∈ x (S(y) ∈ x) [Kunen]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / g. Axiom of Powers VI
Power Set: ∀x ∃y ∀z(z ⊂ x → z ∈ y) [Kunen]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / h. Axiom of Replacement VII
Replacement: ∀x∈A ∃!y φ(x,y) → ∃Y ∀X∈A ∃y∈Y φ(x,y) [Kunen]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / i. Axiom of Foundation VIII
Foundation:∀x(∃y(y∈x) → ∃y(y∈x ∧ ¬∃z(z∈x ∧ z∈y))) [Kunen]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / j. Axiom of Choice IX
Choice: ∀A ∃R (R well-orders A) [Kunen]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / k. Axiom of Existence
Set Existence: ∃x (x = x) [Kunen]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / n. Axiom of Comprehension
Comprehension: ∃y ∀x (x ∈ y ↔ x ∈ z ∧ φ) [Kunen]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / o. Axiom of Constructibility V = L
Constructibility: V = L (all sets are constructible) [Kunen]
7. Existence / A. Nature of Existence / 3. Being / a. Nature of Being
Being is one [Melissus, by Aristotle]
25. Social Practice / F. Life Issues / 3. Abortion
I may exist before I become a person, just as I exist before I become an adult [Lockwood]
It isn't obviously wicked to destroy a potential human being (e.g. an ununited egg and sperm) [Lockwood]
If the soul is held to leave the body at brain-death, it should arrive at the time of brain-creation [Lockwood]
27. Natural Reality / A. Classical Physics / 1. Mechanics / a. Explaining movement
There is no real motion, only the appearance of it [Melissus, by Diog. Laertius]
27. Natural Reality / C. Space / 1. Void
The void is not required for change, because a plenum can alter in quality [Aristotle on Melissus]
27. Natural Reality / E. Cosmology / 2. Eternal Universe
Nothing could come out of nothing [Melissus]