Superfluous matrices in linear complementarity

Superfluous matrices were introduced by Howe in linear complementarity. In general, producing examples of this class is tedious (a few examples can be found in Cottle, Pang and Stone). To overcome this problem, the paper defines a new class of matrices nZ and establish that in nZ superfluous matrices of any order n≥4 can easily be constructed. For every integer k, an example of a superfluous matrix of degree k is exhibited in the end.