“…Data-Driven (DD) solvers seek to determine the material state y ∈ D that is closest to being admissible, in the sense of E, or, alternatively, the admissible state z ∈ E that is closest to being a possible state of the material, in the sense of D. Optimality is understood in the sense of a suitable norm, e. g., for the set-up in Example 2.2, we may choose i. e., we wish to determine the state z ∈ E of the system that is admissible and closest to the data set D, or, equivalently, the point y ∈ D in the material data set that is closest to being admissible. Evidently, if E is affine and D is compact, e. g., consisting of a finite collection of points, then the DD problem (10) has solutions by the Weierstrass extreme-value theorem. More generally, in [7, Cor.…”