Further Reduction of the General Incompleteness Principle
- From: "Charlie-Boo" <shymathguy@xxxxxxxxx>
- Date: 4 Mar 2006 17:18:22 -0800
The basic problem is to generate theorems like the following 4 theorems
of metamathematics:
1. Godel's 1931 1st. Incompleteness Theorem based on Soundness and
Smullyan's Dual Form Theorem (difference not represented here)
2. Rosser's 1936 extension
3. Godel's 1931 1st. Incompleteness Theorem based on w-consistency
-~PRx |-P -> P
-~PRx, PRx |-P => ~|-~P
~PRITx (aA)|-P(A) => ~|-~(aA)P(A)
E.g. the top proof states that if the set of unprovable sentences is
not representable, then if every provable sentence is true then the
logic is incomplete.
(As in earlier post: -~PRx means the nontheorems are not r.e. (or not
representable). PRx means the theorems are r.e. (or representable).
~PRIT means relation "X does not prove Y" is r.e. (or
representable.))
Complete means ~|-P => |-~P. Now drop the x (all statements are of the
form Px P is r.e.) and let:
A = |- It is provable that
B = ~ Not
C = (aA) For all A
P = 0 empty string
and we have:
-~PR A => 0
-~PR , PR A =>BAB
~PRIT CA => BABC
and BA => AB for Complete as exact formalizations of G1-I & S1, R1 and
G1-B. Then consider:
[-] [+] [if] [then]
~PR - A 0
~PR PR A BAB
- ~PRIT CA BABC
Each proof (line) is 4 mutually incompatible conditions:
1. The relations under the [+] are representable.
2. The relations under the [-] are not representable.
3. If the [if] is true for any wff, then the [then] is true for the
same wff.
4. The logic is complete: BA => AB.
This 4 by 3 display gives the 3 proofs that express the theorems. How
do we extend it with more rows?
1. Develop a system (axioms, rules?) to generate these.
2. Generate others.
3. Manually solve other sets of Px and -Px wffs
4. Other relations besides PR, PRIT
C-B
.
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