#concept

godel’s 2 incompleteness theorems are concerned with >> the limits of provability in formal axiomatic theories. Any system that can talk about itself and its own consistency is necessarily inconsistent.

First Incompleteness Theorem >> β€œAny consistent formal systemΒ FΒ within which a certain amount of elementary arithmetic can be carried out is incomplete; i.e., there are statements of the language ofΒ FΒ which can neither be proved nor disproved inΒ F.” [1] Second Incompleteness Theorem >> β€œAssumeΒ FΒ is a consistent formalized system which contains elementary arithmetic. Then F does not prove the consistency of F” [2] True or False: Godel’s first theorem shows there are truths that can’t be proved. Explain ? False. Incompleteness theorem doesn’t deal with provability in an absolute sense, but rather the derivability in a specific formal system. Statement X may be unprovable in formal system A but provable in formal system B. According toΒ GΓΆdel’s incompleteness theorems, the statement that Peano Arithmetic (PA) is consistent, in its guise as a number-theoretic statement (given the technique of godel numbering) ? cannot be derived in PA itself. godel numbering is used to prove these theorems.

References

  1. https://plato.stanford.edu/entries/goedel-incompleteness/

Notes

1st theorem: not complete

  1. any sentence can be represented w a godel number
  2. any proof can be represented w a godel number
  3. the proof referring to itself cannot be represented as a godel number
    1. g: there is no proof with the statement godel g

2nd: can’t prove consistency

my hot takes

but…you kinda got to accept formal system of peano arithmetic, to accept godel numbering… i just think a formal system itself is flawed…logical system…