Integrating plans, which were not originally designed to be used together, is a task that frequently comes up in real world applications. However, this task is typically performed by humans. Contexts enable us to formalize this style of reasoning, thus providing a logical basis for developing computer programs which will be able to mechanically integrate plans produced by different systems.
The main contribution of this section is showing that the techniques we have used for combining data bases or knowledge bases (§4-§6) can be directly applied in combining of plans produced by different planners using different languages.
See any AI textbook, say [50], [51] or the forthcoming [46], for a description of the planning problem.