This is not a set description within the rules of ZF or ZFC.V = { v : (v is not non-finite member of von Neumann ordinals) } = The set of all natural numbers in terms of sets.
This part of the expression insures the entire expression evaluates to false, no matter how you define V.∀v(v∪{v} ∈ V ...
This part does not evaluate at all since cardinality lacks meaning. You need to define your terms....∧ |v∪{v}| < |V|)...
There is no basis for this conclusion. Undefined terms guarantees it, as does the lack of facility with predicate calculus, but since we have already been forewarned of what to expect, we know the conclusion is embedded in the definition. Anything between the definition and this conclusion is unnecessary.which means that |V| is not the cardinality of set V.
Maybe in your fantastical world, but if you stay within the bounds of my definitions, everything works out fine.In other words, you don't have a basis for your X as a non-finite set, and |V| <= |V| is not exceptional exactly because ∀v(v∪{v} ∈ V ∧ |v∪{v}| < |V|).
What does that even mean? A bijection is a mapping with certain properties from one set to another. A bijection among sets? 'Tis a mystery until you explain your usage.One asks: Is there a bijection among all V members?
Sets are not bijective with anything. Mappings can be bijective; sets, not at all.The answer is yes: Given any arbitrary member x in V (where V is the set of all natural numbers in terms of sets) the cardinality of x is |x|, which means that x is bijective with itself.
Care to define what you mean by "no-bijection"? By the way, again, this attempt at another expression would also evaluate to false.But ∀x ∈ V (where x=v or x=v∪{v}) there is no-bijection from v to v∪{v} ∧ ∀v(v∪{v} ∈ V ∧ |v∪{v}| < |V|).
Examples aren't proof.Here it is:...
"Gathered into"?? Be that as it may, if you are referring here to my cardinality definition, it does not require any deconstruction by you to ascertain the meaning of the relational operator I used. It is fully contained in the definition. All you have done is attempted to reach some bogus conclusion by altering the original definition.which means that < (no-bijection) and = (bijection) are not gathered into <= in order to define |V| <= |X|, |V| <= |V|, in the first place.
You haven't come anywhere near establishing anything. You haven't defined what you mean by cardinality, yet.Since |V| is not strictly established, the Cantorian notion of strict cardinality for set V, does not hold water.
At least until you change your mind, again.So once again, thank you ∀
V = { v : (v is not non-finite member of von Neumann ordinals) } = The set of all natural numbers in terms of sets.There is no set of the von Neumann ordinals simply because it is too big to be a set.
In that case the set of all natural numbers in terms of sets, is undefined within the rules of ZF or ZFC.This is not a set description within the rules of ZF or ZFC.
In other words, you are dishonest with yourself.And von Neumann's treatment of the natural numbers is right in line with my point: Just about everything in Mathematics is rooted in Set Theory.
V = { v : (v is not non-finite member of von Neumann ordinals) } = The set of all natural numbers in terms of sets.
In that case the set of all natural numbers in terms of sets, is undefined within the rules of ZF or ZFC.
It is valid because of the following reasons:This is not a valid definition for your set, V. It violates the Axiom of Restricted Comprehension, for example.
It is valid because of the following reasons...
jsfisher said:You can, in fact, use those meanings to show that the expression |A| <= |B| is identical to (|A| < |B|) OR (|A| = |B|)
Definition 1: |A| = |B| iff there is bijection from A to B (where in case of bijection, B can be replaced by A and we get bijection from A to itself).
V = { v : (v is not non-finite member of von Neumann ordinals) } = The set of all natural numbers in terms of sets.
v or v∪{v} are not non-finite sets, where the cardinality of v (notated as |v|) or the cardinality of v∪{v} (notated as |v∪{v}|) is defined (by definition 1) by bijection form a given domain to itself.
Definition 2: |A| < |B| iff (there is injection no surjection from A to B) OR (A=∅ ∧ B~=∅).
∀v ∈ V(v∪{v} ∈ V ∧ |v| < |v∪{v}|) by definition 2, which means that the expression |A| <= |B| (injection from A to B) is not satisfied from v to v∪{v} in V.
Now let's look if |A| <= |B| (injection from A to B) can be used in order to establish |V|.
∀v ∈ V(v∪{v} ∈ V ∧ |v∪{v}| < |V|)
In simple words:
For all v∪{v} in V, |v∪{v}| is too small in order to be valued as |V|, which means that |V| can't be defined as the cardinality of all V members.
In other words: |A| <= |B| (and definitely |V| <= |V|) do not hold water.
As for the set of all natural numbers, |N| is not established.
Definition 1: |A| = |B| iff there is bijection from A to B
You have a compulsion to overstate the obvious and irrelevant, don't you?(where in case of bijection, B can be replaced by A and we get bijection from A to itself)
V = { v : (v is not non-finite member of von Neumann ordinals) } = The set of all natural numbers in terms of sets.
Definition 2: |A| < |B| iff (there is injection no surjection from A to B) OR (A=∅ ∧ B~=∅).
jsfisher said:You can, in fact, use those meanings to show that the expression |A| <= |B| is identical to (|A| < |B|) OR (|A| = |B|)
http://www.internationalskeptics.com/forums/showpost.php?p=13132697&postcount=2Doronshadmi, exactly what post of mine are you quoting in the following?
I start by using your definition of non-finite set, here it is:Not a valid definition. Plus, your "non-finite member" is in jeopardy of being an undefined term.
So not non-finite set is a finite set by your terms.That would be back when I defined a set X to be non-finite when |N| <= |X| (where N is the minimal set satisfying the requirements of the Axiom of Infinity). Since finite and non-finite are complementary terms, defining one automatically defines the other
Great, so by using von Neumann's treatment of the natural numbers, we define V as follows:jsfisher said:And von Neumann's treatment of the natural numbers is right in line with my point: Just about everything in Mathematics is rooted in Set Theory.
Kinda funny, that you don't understand that your definition of non-finite set holds, only if |N| holds.Kinda funny, too, you end up with substantially the same definition for cardinality as I, just with more steps.
A bijection is a mapping with certain properties from one set to another.
V = {
----------------------------------> [B]Bijection[/B] according to [B]Definition 1[/B]
| (order is irrelevant).
| 0 = ∅,
| ↓ [B]No-bijection[/B] according to [B]Definition 2[/B] (order is irrelevant).
| 1 = { ∅ },
| ↓ [B]No-bijection[/B] according to [B]Definition 2[/B] (order is irrelevant).
| 2 = { ∅, {∅} },
| ↓ [B]No-bijection[/B] according to [B]Definition 2[/B] (order is irrelevant).
| 3 = { ∅, {∅} , {∅, {∅}} },
| ↓ [B]No-bijection[/B] according to [B]Definition 2[/B] (order is irrelevant).
| 4 = { ∅, {∅} , {∅, {∅}}, {∅, {∅}, {∅, {∅}}} },
| ↓ [B]No-bijection[/B] according to [B]Definition 2[/B] (order is irrelevant).
|
v
[B]No-Bijection[/B] according to [B]Definition 2[/B] (order is irrelevant).
...
}
Order is not irrelevant since all we is that [B]∀[/B][I]v[/I] ∈ V([I]v[/I]∪{[I]v[/I]} ∈ V)
I start by using your definition of non-finite set, here it is:
So not non-finite set is a finite set by your terms.
Great, so by using von Neumann's treatment of the natural numbers, we define V as follows:
V = { v : (v is not non-finite member of von Neumann's treatment of the natural numbers) } = The set of all natural numbers in terms of sets.
Kinda funny, that you don't understand that your definition of non-finite set holds, only if |N| holds.
Unlike your relative approach that relies on set A and another set B, I first directly define the cardinality of not non-finite set by using the same set, as follows:
Definition 1: |A| = |B| iff there is bijection from A to B (where in case of bijection, B can be replaced by A and we get bijection from A to itself)
So first I am focused on what happens inside set V...
Definition 2: |A| < |B| iff (there is injection no surjection from A to B) OR (A=∅ ∧ B~=∅).
∀v ∈ V(v∪{v} ∈ V ∧ |v| < |v∪{v}|) by definition 2, which means that the expression |A| <= |B| (injection from A to B) is not satisfied from v to v∪{v} in V.
Now let's look if |A| <= |B| (injection from A to B) can be used in order to establish |V|.
Wrong, jsfisher, in case that you have missed it, I start by using your definition of "finite set".Since your latest definition for "finite set" depends on your definition(s) for cardinality, you'll need to save it until later. The term is undefined until you've adequately defined cardinality.
Wrong again jsfisher, at this stage I still use your definition of the term "non-finite member".Wrong on two counts (still). The term "non-finite member" is not (yet) defined, and your set-builder formulation falls outside what is allowed.
Yes I already aware of your religious approach about definitions.Definitions don't "hold". They simply define.
It is a "direct approach" since the bijection is done from A to itself, where v is not non-finite member (still by your definition of non-finite) of von Neumann's treatment of the natural numbers, which is right in line with your point, isn't it jsfisher?That's still a "relative approach", and you have provided nothing to restrict it to non-finite sets.
Wrong, definition 1 directly defines the cardinality of a not non-finite member v (in set V) by bijection from v to itself, where |V| is not considered at all at this stage.Congratulations. Your Definition 1 establishes that |V| = |V| and that for all v in V, |v| = |v|
Again, at this stage we argue only about what is inside set V, such that v is not non-finite member (still by your definition of non-finite) of von Neumann's treatment of the natural numbers, which is right in line with your point.I doubt this is what you really mean. By this definition |V| < |V|. You need more words for the left side of the OR (and you don't need the rest of the OR at all).
Wrong again, bijection (=) is from v to itself in V, where injection non-surjection (<) is from |v| to |v ∪ {v}| or form ∅ to ~∅ in V (anything about V is not considered yet, but only about what within it.)Why not? If |v| < |v ∪ {v}| (your definition) then there must be an injection from v to V.
V = {
----------------------------------> [B]Bijection[/B] according to [B]Definition 1[/B]
| (order is irrelevant).
| 0 = ∅,
| ↓ [B]No-bijection[/B] according to [B]Definition 2[/B] (order is irrelevant).
| 1 = { ∅ },
| ↓ [B]No-bijection[/B] according to [B]Definition 2[/B] (order is irrelevant).
| 2 = { ∅, {∅} },
| ↓ [B]No-bijection[/B] according to [B]Definition 2[/B] (order is irrelevant).
| 3 = { ∅, {∅} , {∅, {∅}} },
| ↓ [B]No-bijection[/B] according to [B]Definition 2[/B] (order is irrelevant).
| 4 = { ∅, {∅} , {∅, {∅}}, {∅, {∅}, {∅, {∅}}} },
| ↓ [B]No-bijection[/B] according to [B]Definition 2[/B] (order is irrelevant).
|
v
[B]No-Bijection[/B] according to [B]Definition 2[/B] (order is irrelevant).
...
}
Order is not irrelevant since all we is that [B]∀[/B][I]v[/I] ∈ V([I]v[/I]∪{[I]v[/I]} ∈ V)
1) First I use your definitions, which define the complement terms "non-finite" and "finite" (which I write as "not non-finite")
2) Then I use von Neumann's treatment of the natural numbers, which is right in line with your point, in order to define V not non-finite members, which are v and v∪{v}.
3) Then I directly define the cardinality for all v in V, by bijection (=) from v to itself.
4) Than I indirectly define the cardinality for all v and v∪{v, by injection non-surjection (<) from v to v∪{v or from ∅ to ~∅, in V.
5) (3) and (4) are done within V, at this stage.
6) Only than I use (4) in order to show that |V| is too big in order to be valued as the cardinality of set V, simply because
∀v ∈ V(v∪{v} ∈ V ∧ |v| < |v∪{v}| < |V|).
snip
1) First I use your definitions, which define the complement terms "non-finite" and "finite" (which I write as "not non-finite")
That definition requires an already existing definition for cardinality. You cannot use mine because you reject it.
0 = ∅
1 = { ∅ }
2 = { ∅, {∅} }
3 = { ∅, {∅} , {∅, {∅}} }
4 = { ∅, {∅} , {∅, {∅}}, {∅, {∅}, {∅, {∅}}} }
...
Let's simplify it for you....
Yes they are at issue.My definitions aren't at issue.