CAD Overlay CAD Overlay CAD Overlay is a commercial software application for raster-to-vector translation in 2D computer-aided design (CAD) and drafting — available between 1988 and 1996 as a third-party application for AutoCAD and other CAD systems. Developed and marketed by Image Systems Technology, CAD Overlay was first released in January 1988 running on AutoCAD Version 2.6. CAD Overlay replaced the previous generation of automatic raster-to-vector translation systems by embedding scanned documents and images directly in the CAD system. CAD Overlay was derived from a custom AutoCAD application developed using the Nth Engine graphics board in 1987 by David Chassin for Image
Computer-assisted proof the runtime environment and hardware. Other mathematicians believe that lengthy computer-assisted proofs should be regarded as "calculations", rather than "proofs": the proof algorithm itself should be proved valid, so that its use can then be regarded as a mere "verification". Arguments that computer-assisted proofs are subject to errors in their source programs, compilers, and hardware can be resolved by providing a formal proof of correctness for the computer program (an approach which was successfully applied to the four-color theorem in 2005) as well as replicating the result using different programming languages, different compilers, and different computer hardware. Another possible way