From: zuhair on
Theorems:

theorem: Exist x for all y ( y e x <-> y is a set )
proof: let phi<-> y is a set
substitute in classes.QED

theorem: Exist! x for all y ( y e x <-> y is a set )
proof: Extensionality

Define(V):- x=V <-> for all y ( y e x <-> y is a set )

theorem: Exist x for all y ~ y e x
proof:let phi <-> ~y=y
substitute in classes.QED

theorem: Exist! x for all y ~ y e x
proof: Extensionality

Define(0):- x=0 <-> for all y ( ~ y e x )

theorem: for every set a Exist x For all y ( y e x <-> y=a )
proof: let phi <-> y=a
since a is a set then from classes we'll have the set theorem
above.QED

theorem: for every set a Exist! x For all y ( y e x <-> y=a )
proof: Extensionality

Define: x={a} <-> for all y ( y e x <-> y=a )

theorem: for all x: ~ x e x
proof: suppose Exist x: x e x
then {x} would not be disjoint of x
violating foundation.

from that we have ~ V e V.

Now it is clear that from classes we can have a class that is an
unordered pair of any two sets, from that we can define ordered pair
in Kuratowski manner, also we can separation and replacement of
sets,
unions both finite and infinite also can be defined, but all these
are
classes the set-hood of which is not yet determined.

theorem: 0 is a set.
proof: let phi<-> ~y=y
substitute in Sets and we get
c={y|~y=y}
Now ~y=y has no parameter and no constant in it

so we need to check the following first:

for all c,z ((c={y|~y=y} & c subclass z) -> z=z))

which is trivially true.

now we check the next condition:

~for all x ( Mx ->Exist y (~y=y & x e y))

since from axiom 3 we do have at least on set existing, then the
above
condition would be fulfilled since Exist y (~y=y & x e y) is
trivially
false, then for all x ( Mx ->Exist y (~y=y & x e y)) is trivially
false , so its
negation is ture.

Now we check the proper subformulas condition, now the only proper
subformula of ~y=y is the formula y=y so we only need to prove the
following:

~for all y (My~y=y<->Myy=y)

since there exist at least one set (axiom 3) then the above sentence
is trivially true.

thus all conditions in the antecedent of SETS schema are fulfilled,
thus the class {y|~y=y} is a set, thus 0 is a set.

pairing,union,power,separation and replacement of sets all can be
proved in this theory, so is infinity . Proofs shall be posted later.

So it appears as if MK is a equivalent to this theory?

Zuhair
From: zuhair on
Theorems:

theorem: Exist x for all y ( y e x <-> y is a set )
proof: let phi<-> y is a set
substitute in classes.QED

theorem: Exist! x for all y ( y e x <-> y is a set )
proof: Extensionality

Define(V):- x=V <-> for all y ( y e x <-> y is a set )

theorem: Exist x for all y ~ y e x
proof:let phi <-> ~y=y
substitute in classes.QED

theorem: Exist! x for all y ~ y e x
proof: Extensionality

Define(0):- x=0 <-> for all y ( ~ y e x )

theorem: for every set a Exist x For all y ( y e x <-> y=a )
proof: let phi <-> y=a
since a is a set then from classes we'll have the set theorem
above.QED

theorem: for every set a Exist! x For all y ( y e x <-> y=a )
proof: Extensionality

Define: x={a} <-> for all y ( y e x <-> y=a )

theorem: for all x: ~ x e x
proof: suppose Exist x: x e x
then {x} would not be disjoint of x
violating foundation.

from that we have ~ V e V.

Now it is clear that from classes we can have a class that is an
unordered pair of any two sets, from that we can define ordered pair
in Kuratowski manner, also we can separation and replacement of
sets,unions both finite and infinite also can be defined, but all
these
are classes the set-hood of which is not yet determined.

theorem: 0 is a set.
proof: let phi<-> ~y=y
substitute in Sets and we get
c={y|~y=y}
Now ~y=y has no parameter and no constant in it

so we need to check the following first:

for all c,z ((c={y|~y=y} & c subclass z) -> z=z))

which is trivially true.

now we check the next condition:

~for all x ( Mx ->Exist y (~y=y & x e y))

since from axiom 3 we do have at least on set existing, then the
above condition would be fulfilled since Exist y (~y=y & x e y) is
trivially false, then for all x ( Mx ->Exist y (~y=y & x e y)) is
trivially
false , so its negation is ture.

Now we check the proper subformulas condition, now the only proper
subformula of ~y=y is the formula y=y so we only need to prove the
following:

~for all y (My~y=y<->Myy=y)

since there exist at least one set (axiom 3) then the above sentence
is trivially true.

thus all conditions in the antecedent of SETS schema are fulfilled,
thus the class {y|~y=y} is a set, thus 0 is a set.

pairing,union,power,separation and replacement of sets all can be
proved in this theory, so is infinity . Proofs shall be posted later.

So it appears as if MK is a equivalent to this theory?

Zuhair
From: zuhair on
Theorems:

theorem: Exist x for all y ( y e x <-> y is a set )
proof: let phi<-> y is a set
substitute in classes.QED

theorem: Exist! x for all y ( y e x <-> y is a set )
proof: Extensionality

Define(V):- x=V <-> for all y ( y e x <-> y is a set )

theorem: Exist x for all y ~ y e x
proof:let phi <-> ~y=y
substitute in classes.QED

theorem: Exist! x for all y ~ y e x
proof: Extensionality

Define(0):- x=0 <-> for all y ( ~ y e x )

theorem: for every set a Exist x For all y ( y e x <-> y=a )
proof: let phi <-> y=a
since a is a set then from classes we'll have the set theorem
above.QED

theorem: for every set a Exist! x For all y ( y e x <-> y=a )
proof: Extensionality

Define: x={a} <-> for all y ( y e x <-> y=a )

theorem: for all x: ~ x e x
proof: suppose Exist x: x e x
then {x} would not be disjoint of x
violating foundation.

from that we have ~ V e V.

Now it is clear that from classes we can have a class that is an
unordered pair of any two sets, from that we can define ordered pair
in Kuratowski manner, also we can separation and replacement of
sets,unions both finite and infinite also can be defined, but all
these are classes the set-hood of which is not yet determined.

theorem: 0 is a set.
proof: let phi<-> ~y=y
substitute in Sets and we get
c={y|~y=y}
Now ~y=y has no parameter and no constant in it

so we need to check the following first:

for all c,z ((c={y|~y=y} & c subclass z) -> z=z))

which is trivially true.

now we check the next condition:

~for all x ( Mx ->Exist y (~y=y & x e y))

since from axiom 3 we do have at least on set existing, then the
above condition would be fulfilled since Exist y (~y=y & x e y) is
trivially false, then for all x ( Mx ->Exist y (~y=y & x e y)) is
trivially false , so its negation is true.

Now we check the proper subformulas condition, now the only proper
subformula of ~y=y is the formula y=y so we only need to prove the
following:

~for all y (My~y=y<->Myy=y)

since there exist at least one set (axiom 3) then the above sentence
is trivially true.

thus all conditions in the antecedent of SETS schema are fulfilled,
thus the class {y|~y=y} is a set, thus 0 is a set.

pairing,union,power,separation and replacement of sets all can be
proved in this theory, so is infinity . Proofs shall be posted later.

So it appears as if MK is a equivalent to this theory?

Zuhair
From: zuhair on
On Nov 10, 8:16 pm, zuhair <zaljo...(a)yahoo.com> wrote:
> NST2: is the set of all sentences entailed (from FOL with identity
> and e) by the following non logical axioms below the following
> definition of the notion "set" denoted by M:
>
> Define(set): x is a set <-> Exist y ( x e y )
>
> Define(M):  Mx <-> x is a set.
>
> 1. Extensionality: for all z ( z e y <-> z e x)  -> x=y
>
> 2. Foundation: Exist y y e x -> Exist y (y e x & y disjoint x)
>
> 3. Classes: If phi is a formula in which at least y is free, and in
> which x is not free, then all closures of
>
> Exist x for all y ( y e x <-> My phi )
>
> are axioms.
>
> Define: x={y|phi} <-> for all y ( y e x <-> My phi )
>
> 4. Set existence: Exist x: x is a set.
>
> Q is a proper substring of phi, means that Q is a substring of phi
> and Q is not the formula phi.
>
> Q is said to be a proper subformula of phi if
> Q is a proper substring of phi that is a formula, that has the same
> principal free variable as phi, and the set of all parameters of Q is
> a subset of the set of all parameters of phi.
>
> 5. Sets:If phi is a formula in which at least y or z are free, and in
> which c is not free, with parameters x1,...,xn, and constants
> k1,...,kp , and Q1,...,Qm are all proper subformulas of phi, then all
> closures of:
>
> Mx1,...,Mxn & Mk1,...,Mkp
> for all c,z ((c={y|phi} & c subclass z) -> ~ phi(z)) &
> ~for all x ( Mx ->Exist y (phi(y) & x e y)) &
> ~for all y (Myphi<->MyQ1)&...&~for all y(Myphi<->MyQm)
>
> -> Exist c (Mc & for all y ( y e c <-> phi )
>
> are axioms.
>
> Theory definition finished/
>
> Theorems with proofs shall be posted later.
>
> Zuhair

This theory is inconsistent, simply take Phi to be
" y is singleton and for all z ( z e y -> z is singleton )"

Then we'll have the set {y|phi} were phi is the above formula,
rendering the theory inconsistent since the union of this set is the
class of all sets which will be a set, now this theory prove that the
subset of any set is a set, thus the Russell class would be a set,
which is an obvious contradiction!

Zuhair