The Object Centered Language Manual
The approach of the object-centred method could be summed up as providing a tool-supported language for domain modellers to engineer the capture of planning domain models, and then subsequently operationalise those models. The idea is to provide the domain developer with a structured language that allows models to be constructed, statically validated and maintained with relative ease.
This approach utilises the notion of ``lifting'' a domain model from the level of the literal to the level of a more abstract object-centred representation. As well as helping in the development of a domain model, the object-centred representation has advantages in the development and resulting efficiency of planning algorithms. OCL has a set of planning support tools which are continually being developed. The tools provide the modeller with opportunities to improve the model with respect to its fit with the domain and its completeness and efficiency when used at planning time. For example, a random task generator tool can automatically generate random tasks for any sound model in OCL, without the need for domain-specific software.
In this manual we introduce OCL using the concrete syntax of OCLh, the language variant that can be used for both precondition planning and HTN planning.