Incompleteness

"An introduction to the life and thought of Kurt Gödel, who transformed our conception of math forever"--Provided by publisher.

Based on the author's thesis (Doctoral--University of Hong Kong, 2005).

Kurt Godel, the greatest logician of our time, startled the world of mathematics in 1931 with his Theorem of Undecidability, which showed that some statements in mathematics are inherently "undecidable." His work on the completeness of logic, the incompleteness of number theory, and the consistency of the axiom of choice and the continuum theory brought him further worldwide fame. In this introductory volume, Raymond Smullyan, himself a well-known logician, guides the reader through the fascinating world of Godel's incompleteness theorems. The level of presentation is suitable for anyone with a basic acquaintance with mathematical logic. As a clear, concise introduction to a difficult but essential subject, the book will appeal to mathematicians, philosophers, and computer scientists.

Gödel's true-but-unprovable sentence from the first incompleteness theorem is purely logical in nature, i.e. not mathematically natural or interesting. An interesting problem is to find mathematically natural and interesting statements that are similarly unprovable. A lot of research has since been done in this direction, most notably by Harvey Friedman. A lot of examples of concrete incompleteness with real mathematical content have been found to date. This brief contributes to Harvey Friedman's research program on concrete incompleteness for higher-order arithmetic and gives a specific example of concrete mathematical theorems which is expressible in second-order arithmetic but the minimal system in higher-order arithmetic to prove it is fourth-order arithmetic. This book first examines the following foundational question: are all theorems in classic mathematics expressible in second-order arithmetic provable in second-order arithmetic? The author gives a counterexample for this question and isolates this counterexample from the Martin-Harrington Theorem in set theory. It shows that the statement “Harrington's principle implies zero sharp" is not provable in second-order arithmetic. This book further examines what is the minimal system in higher-order arithmetic to prove the theorem “Harrington's principle implies zero sharp" and shows that it is neither provable in second-order arithmetic or third-order arithmetic, but provable in fourth-order arithmetic. The book also examines the large cardinal strength of Harrington's principle and its strengthening over second-order arithmetic and third-order arithmetic.

Central to the Jensen Memorial Lectures 2023 is an invitation to take incompleteness seriously in how we imagine, relate to and seek to understand a world in perpetual motion. Despite our instinct for and obsession with completeness, we are constantly reminded that the sooner one recognises and provides for incompleteness and the conviviality it inspires as the normal way of being, the better we are for it. Fluidity, compositeness and the capacity to be present in multiple places and forms simultaneously in whole or in fragments are core characteristics of reality and ontology of incompleteness. How would we frame our curiosities and conversations about processes, relationships and phenomena with an understanding of the universality of incompleteness and mobility? West and Central Africa, for example, are regions where it is commonplace to embrace and celebrate incompleteness in nature, the suprasensory, human beings, human actions, human inventions and human achievements. The lectures indicate how we could draw inspiration in this regard to inform current clamours for decolonisation and the growing ambivalence about rapid advances in digital technologies (artificial intelligence (AI) in particular), as well as with twenty-first century concerns about migrants and strangers knocking at the doors of opportunities we feel more entitled to as bona fide citizens and insiders. The lectures draw on the writings of Amos Tutuola as well as from popular ideas of personhood and agency in Africa, to make a case for sidestepped and silenced traditions of knowledge. They highlight Africa’s possibilities, prospects and emergent capacities for being and becoming in tune with the continent’s creativity and imagination. They speak to the nimble-footed flexible-minded frontier African at the crossroads and junctions of myriad encounters, facilitating creative conversations and challenging regressive logics of exclusionary claims and articulation of identities and achievements. The traditions of knowledge discussed in these lectures do not only speak to Africans, but to the world, as the philosophies explored have universal application. “The crucial anthropological question of relationality and othering is at the heart of this original and enlightening book. Nyamnjoh cautions the missionaries of decoloniality against the risk of substituting one illusion of completeness with another. For him, incompleteness is the basis of any healthy exchange. He therefore recommends embracing the universality of incompleteness in motion and taking seriously an ancestral tradition of self-extension through creative imagination in this anxious age of artificial intelligence. Forcefully argued and abundantly substantiated – with finesse and laughter that run through it – this book will be a milestone by making us rediscover the demands and the magic of fieldwork.” Prof. Dr. Mamadou Diawara, Goethe University, Frankfurt/Main Frobenius-Institut, Frankfurt/Main Point Sud, Bamako, Mali

This introduction to mathematical logic takes Gödel's incompleteness theorem as a starting point. It goes beyond a standard text book and should interest everyone from mathematicians to philosophers and general readers who wish to understand the foundations and limitations of modern mathematics.

This volume presents some of the main areas and results of general metamathematics, including the results of Gödel et al. on incompleteness.

"Incompleteness At Every Turn" This book is a journey of incompleteness in which every story is wandering somewhere in search of its completeness. Ask yourself the answer to each story and see what answer your heart gives. I believe you will always get a positive answer. Whenever negativity develops inside us, our desires overpower us at that moment. We are not able to understand the difference between right and wrong. But in the meantime, if we find a small pitiful scene, then the unit of positivity within us gets awakened. Believe me, this unit of positivity is the identity of this human life. We have to fight the incompleteness within us and become thirsty and search for the well. If we reach near this well, our thirst will be quenched for a few moments by the water of that well. Life also has the same relation with incompleteness. We try to complete what we know is incomplete. After it is complete, some more incompleteness become visible. Just like drinking water from a well once quenches thirst only for a few moments. After some time, we feel thirsty again and we need water again. This same cycle continues in our lives between incompleteness and life. Therefore, we should always keep moving forward while fighting this.