Hi all, I've written a paper on computational category theory but have for a while been unable to determine whether or not my methods or results are new. I would greatly appreciate any input from the community on this matter. The paper, "Proper Diagrams for Constructing Presheaf-Valued Limits", is about the construction of limits of diagrams of presheaves. The content is not too deep mathematically and is aimed more at computation. The basic idea is that given a functor D from a small category C into a category of presheaves, I construct a second functor D' of the same type where there is a natural transformation D'->D whose components are monomorphisms. The construction has the property that the limit of D is isomorphic to the limit of D'. The intuition is that we remove parts of the presheaves so that the computation of the limit is easier. I like to think of this approach as orthogonal to the use of initial functors to construct limits. Both methods preserve the limit but initial functors reduce the number of objects in the domain of a diagram whereas our transformation reduces the objects in the codomain of the diagram. A concise version of the paper is available at https://www.cs.tcd.ie/Shane.OConchuir/limits/limitspaper.pdf A draft technical report with the missing proofs and some appendices is available at https://www.cs.tcd.ie/Shane.OConchuir/limits/limitstr.pdf The technical report explains how I derived my definition of "spare" element. Any comments, corrections, criticisms, or references are welcome. In particular, I would like to know if any of this seems familiar (apologies in advance!) Also, my choice of terminology ("proper", "inconsistent") probably conflicts with normal use and one of my constructions, 'final proper diagram', may well be called 'initial proper diagram'. Many regards, Shane O'Conchuir Department of Computer Science Trinity College Dublin