TY  - BOOK
AU  - Girard,Jean-Yves
AU  - Girard,Jean-Yves
TI  - The Blind Spot: Lectures on Logic 
SN  - 9783037195888
PY  - 2011///
CY  - Zuerich, Switzerland
PB  - European Mathematical Society Publishing House
KW  - Mathematical logic
KW  - bicssc
KW  - Mathematical logic and foundations
KW  - msc
KW  - Category theory; homological algebra
KW  - Computer science
N1  - Restricted to subscribers
N2  - These lectures on logic, more specifically proof theory, are basically intended for postgraduate students and researchers in logic.   The question at stake is the nature of mathematical knowledge and the difference between a question and an answer, i.e., the implicit and the explicit. The problem is delicate mathematically and philosophically as well: the relation between a question and its answer is a sort of equality where one side is “more equal than the other”: one thus discovers essentialist blind spots.  Starting with Gödel’s paradox (1931) – so to speak, the incompleteness of answers with respect to questions – the book proceeds with paradigms inherited from Gentzen’s cut-elimination (1935). Various settings are studied: sequent calculus, natural deduction, lambda calculi, category-theoretic composition, up to geometry of interaction (GoI), all devoted to explicitation, which eventually amounts to inverting an operator in a von Neumann algebra.  Mathematical language is usually described as referring to a preexisting reality. Logical operations can be given an alternative procedural meaning: typically, the operators involved in GoI are invertible, not because they are constructed according to the book, but because logical rules are those ensuring invertibility. Similarly, the durability of truth should not be taken for granted: one should distinguish between imperfect (perennial) and perfect modes. The procedural explanation of the infinite thus identifies it with the unfinished, i.e., the perennial. But is perenniality perennial? This questioning yields a possible logical explanation for algorithmic complexity.  This highly original course on logic by one of the world’s leading proof theorists challenges mathematicians, computer scientists, physicists and philosophers to rethink their views and concepts on the nature of mathematical knowledge in an exceptionally profound way
UR  - https://doi.org/10.4171/088
UR  - http://www.ems-ph.org/img/books/girard_mini.jpg
ER  -