This is a preview. Log in through your library . Abstract We present a counterexample to the conjecture by Orlik that the restriction of a free hyperplane arrangement to one of its hyperplanes is free ...

Consider a pencil lying on your desk. Try to spin it around so that it points once in every direction, but make sure it sweeps over as little of the desk’s surface as possible. You might twirl the ...

The process of proofs and refutations described by Lakatos is essential in school mathematics to provide students with an opportunity to experience how mathematical knowledge develops dynamically ...

Quantified Boolean Formulas (QBF) extend classical Boolean logic by incorporating quantifiers over Boolean variables, thereby enabling the expression of problems in the PSPACE complexity class. The ...