On May 20, 8:48 pm, Charlie-Boo <
shymath...@gmail.com> wrote:
> On May 20, 1:31 am, Graham Cooper <
grahamcoop...@gmail.com> wrote:
>
> > ...
>
> > > a1 = 8203215
> > > not(proof(8203215)
>
> > The above formula refers to itself !
>
> > Herc
>
> Yes, and a fine job indeed. But let us abstract UP and generalize.
> We have neither digits, numerals nor constant considerations. We have
> only sets and functions.
OK but you need SOME functionality in your parameters.
Be it
call by name sqrt(X)
call by value sqrt(2)
call by line number, godel number..
20 not proof(20)
or
G<->not(proof(G))
are fine too, it depends what TYPE the domain of your functions are.
> We have Q, defined to be (all A)(exists B)
> LT(A,B) ^ P(B) ^ P(f(B)) where P be a recursive set and f(I) be a
> recursive function. You have the recursive relation x proves y, the
> r.e. set x is provable, the recursive function f(x)=y iff x proves y.
> Let us pay homage to Godel, for He created the undecidable sentence
> and decided it is true. How did he construct that temple from the
> wisdom in his head? When will the Godel Sentence G be the same as the
> C-B Sentence Q?
>
> You must express "wff number x with x substituted for its free
> variable is not provable", or, expanding your possibilities, realize
> that,
>
> "When any one of these sets [the true, provable and unrefutable
> sentences] P, is expressible or representable, the sentence
> that expresses or represents, respectively, 'This is in P.' is
> undecidable." This includes:
>
> 1. Since unprovability is expressible: The sentence that expresses
> "This is not provable." is undecidable.
> 2. Since refutability is expressible: The sentence that expresses
> "This is refutable." is undecidable.
> 3. Since refutability is representable: The sentence that represents
> "This is refutable." is undecidable.
>
>
http://www.cs.nyu.edu/pipermail/fom/2010-July/014933.html
>
> When is each of these Q?
>
> C-B
You need to define provable in a more functional method.
GODEL = no PROVE(X) predicate
TARSKI = and no TRUE(X) either
isn't helping the poor old programmer!
As far as PROGRAMMING IN LOGIC is concerned.
2+1=3 ?
and
PROVE( 2+1=3 )
is just selecting the [TRACE=ON ] button!
----------------
That is why I simplified my provability predicate in Provable Set
Theory.
OLD
XeS<->p(X) <-> provable( XeS<->p(X) )
not(provable(X)) <-> provable(not(X))
provable(THM) <-> provable(A) ^ provable(B) ^ provable(A^B->THM)
-----------------
Godel was right in a way - YOU JUST CANT PROGRAM PROVABLE()!
it reduces down to the same as:
TRUE-WFF(X)
THEOREM(X)
DERIVE(X)
TRUE(X)
SOLVE(X)
THM(X)
T(X)
So THM(X) <-> NOT(PROVABLE(NOT(X)))
can just be done with double negation.
F<->F
~(F<->~F) %NO CONTRADICTIONS!
..
XeS<->p(X) <-> XeS<->p(X)
RUSSELLSET <-> (CONTRADICTION)
RUSSELLSET <-> FALSE
~EXIST(rs) rs<->x~ex
---------------------
I can't help any further because I simply don't have a predicate for
PROVE(THM)
t(R,z(Z)) :- if(L,R) , t(L,Z).
Where does it go?
Herc