By Dov M. Gabbay, Heinrich Wansing

The thought of negation is among the crucial logical notions. it's been studied due to the fact that antiquity and has been subjected to thorough investigations within the improvement of philosophical good judgment, linguistics, man made intelligence and common sense programming. The homes of negation-in blend with these of different logical operations and structural positive aspects of the deducibility relation-serve as gateways between logical platforms. for this reason negation performs a huge function in determining logical structures for specific functions. for the time being negation is a 'hot topic', and there's an pressing desire for a accomplished account of this logical key thought. We as a result have requested best students in a variety of branches of good judgment to give a contribution to a quantity on "What is Negation?". the result's the current smartly centred choice of re­ seek papers bringing jointly diversified methods towards a normal characteri­ zation of sorts of negation and classifications thereof. the quantity is established into 4 interrelated thematic elements. half I is founded round the subject matters of types, Relevance and Impossibility. In bankruptcy 1 (Negation: issues of View), Arnon Avron develops characteri­ zations of negation, one semantic the opposite proof-theoretic. curiously and perhaps provokingly, less than neither of those bills intuitionistic negation emerges as a real negation. J. Michael Dunn in bankruptcy 2 (A Comparative examine of assorted Model-theoretic remedies of Negation: A background of Formal Negation) surveys an in depth correspondence-theoretic classifcation of varied notions of negation when it comes to homes of a binary relation interpreted as incompatibility.