The Gödel Incompleteness Theorem and Decidability over a Ring
Here we give an exposition of Gödel’s result in an algebraic setting and also a formulation (and essentially an answer) to Penrose’s problem. The notions of computability and decidability over a ring R underly our point of view. Gödel’s Theorem follows from the Main Theorem: There is a definable undecidable set ovis Z. By way of contrast, Tarski’s Theorem asserts that every definable set over the reals or any real closed field R is decidable over R. We show a converse to this result: Any sufficiently infinite ordered field with this latter property is necessarily real closed.
KeywordsFinite Extension Incompleteness Theorem Real Closed Field Computable Isomorphism Weak Conjecture
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