11. For all x \ in X, where I _ C is the indicator function of C. 12. The hinge loss provides a relatively tight, convex upper bound on the 0 1 indicator function . 13. In many cases, such as order theory, the inverse of the indicator function may be defined. 14. It may be described as the " indicator function of 1 " within the set of positive integers. 15. Denote the number of subsets to which belongs, where we use the indicator functions of the sets. 16. As a counterexample, take " f " to be the indicator function of some equidistributed sequence. 17. Also, projections ( i . e . self-adjoint idempotents ) correspond to indicator functions of clopen sets. 18. Thus the indicator function of " B " does not agree with any column in at least one entry. 19. Except on a set of probability zero, where 1 _ A is the indicator function of " A ". 20. So, for example, when a theory defines the concept of a characteristic function or the indicator function of a relation.
