Herschend–Liu–Nakaoka introduced the notion of an n-exangulated category. It is not only a higher dimensional analogue of extriangulated categories defined by Nakaoka–Palu, but also gives a simultaneous generalization of n-exact categories and
$$(n+2)$$
-angulated categories. In this article, we give an n-exangulated version of Auslander’s defect and Auslander–Reiten duality formula. Moreover, we also give a classification of substructures (=closed subbifunctors) of a given skeletally small n-exangulated category by using the ca...
