CAD data exchange use by design, must be a part of the data exchange system. STEP-NC was designed to carry GD&T and other PMI through CAD and CAM into a CNC. CAD data exchange CAD data exchange is a modality of data exchange used to translate data between different Computer-aided design (CAD) authoring systems or between CAD and other downstream CAx systems. Many companies use different CAD systems internally and exchange CAD data with suppliers, customers and subcontractors. Transfer of data is necessary so that, for example, one organization can be developing a CAD model, while another performs analysis work on the same
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