GENIE-V3 concepts document

The GENIE data analysis program is a program used for analysis of data from the ISIS neutron scattering instruments. The current version, GENIE-V2, is now being re-written to provide a much more powerful data analysis system for the next major version of the program, GENIE-V3. The purpose of this ''Concepts Document'' is to establish a frame of reference within which to discuss the development of GENIE-V3. It does not seek to define everything which will be implemented in the new version of the GENIE program. A substantial amount of design effort has been expended to produce a plausible design for the language and operation of GENIE-V3. Having said this, this is in no way a complete specification. Several features (although intended for any working version of GENIE-V3) have not been documented here, hopefully though, nothing material has been left out. To keep this document to a reasonable length, commands which can be written using GENIE-V3 are omitted. (author)