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A classical problem posed in 1992 by Huijsmans and de Pagter asks whether, for every positive operator on a Banach lattice with spectrum , the inequality holds true. While the problem remains unsolved in its entirety, a positive solution is known in finite dimensions. In the broader context of ordered Banach spaces, Drnovšek provided an infinite-dimensional counterexample. In this note, we demonstrate the existence of finite-dimensional counterexamples, specifically on the ice cream cone and on a polyhedral cone in . On the other hand, taking inspiration from the notion of -isometries, we establish that each counterexample must contain a Jordan block of size at least .

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