“…A map of DLR pX, L, ρq and pY, M, µq is given by a function f : X Ñ Y (hence no Lipschitz or other continuity conditions are asked) together with an auxiliary map ϕ : X ˆX ˆL Ñ Y which, intuitively, tracks errors in input into errors in output; more formally, ϕ must satisfy, for all x, y P X and ǫ P L, that if ρpx, ǫ, yq holds, then both µpf pxq, ϕpx, y, ǫq, f pyqq and µpf pxq, ϕpx, y, ǫq, f pyqq also hold. (Separated) DLR and their maps form a cartesian closed category DLR (see the Appendix, and [13,28] for further details).…”