At the University of Vaasa in Finland, mathematician Yosra Barkaoui has successfully generalized a fundamental theorem that had remained confined to “bounded” systems for more than 40 years.

For a space S of psychological sensations such as the brightness-color cone of colorimetry, we suppose an empirical preorder ⩽ given on the Cartesian product S x S, where (s1, s2) ⩽ (t1, t2) connotes ...