 the infimum over all possible hyperplanes) is called the minimal width of "C", "w"("C").The (closed) set of points "P" between two distinct, parallel hyperplanes in R"n" is called a plank, and the distance between the two hyperplanes is called the width of the plank, "w"("P").Tarski conjectured that if a convex body "C" of minimal width "w"("C") was covered by a collection of planks, then the sum of the widths of those planks must be at least "w"("C").