Showing papers by "Jean-Yves Girard published in 2001"

Locus Solum: From the rules of logic to the logic of rules

Abstract: Go back to An-fang, the Peace Square at An-Fang, the Beginning Place at An-Fang, where all things start (…) An-Fang was near a city, the only living city with a pre-atomic name (…) The headquarters of the People Programmer was at An-Fang, and there the mistake happened: A ruby trembled. Two tourmaline nets failed to rectify the laser beam. A diamond noted the error. Both the error and the correction went into the general computer. Cordwainer Smith The Dead Lady of Clown Town, 1964.

Locus Solum: From the Rules of Logic to the Logic of Rules

Abstract: Logic is no longer about a preexisting external reality, but about its own protocols, its own geometry. Typically the negation is not about saying "NOT", but about the mirror, the duality "I" vs. "the world"... The new approach encompasses the old one, typically if "I" win, "the world" loses, i.e., wins "NOT". When logical artifacts are identified with their own rules of production, LOCATIVE phenomenons arise. In particular, one realises that usual logic (including linear logic) is SPIRITUAL, i.e., up to isomorphism. But there is a deeper locative level, with indeed a more regular structure. Typically the usual (additive) conjunction has the value of categorical product in usual logic, and enjoys commutativity, associativity, etc. up to isomorphism. In ludics, what corresponds is a plain intersection G ∩ H, which is really associative, commutative, etc. (no isomorphisms); it contains the usual conjunction as a delocalised case ϕ(G) ∩ ψ(H). Incidentally this shows that the categorical view of logic - if very useful - is wrong... Nature abhors an isomorphism! LUDICS is a monist approach to logic-without this nonsense distinction syntax/semantics/meta - just plain logical artifacts, period.