FAQ

There is a graphical debugger in SWI Prolog that is very useful to go through your program step by step, inspect the variable bindings and the open choice points.

KnowRob is implemented in a combination of OWL, Prolog and Java. When creating extensions, it is worth considering which language to implement them in:

• Description language, no programming language
• Class taxonomy of objects, actions, events,…
• Instances of these classes (e.g. environment models, experiences)
• Robot capabilities/action requirements

• Logical programming language: conceptually close to the knowledge representation, good at searching and pattern matching
• Useful for functionality interacting closely with the internal representation (OWL gets parsed into Prolog triples)
• Wrapper predicates to simplify commonly used queries, inference predicates (DL inference, computables,…)
• Functionality involving (recursive) search, graph matching, reasoning about ontological structure, …

• Object-oriented programming language that can interact with Prolog via the JPL interface
• Conceptually further away from the internal knowledge representation
• Good library support, therefore useful for external interfaces (WWW, ROS,…) and for integrating libraries (ProbCog, Weka, Visualization…)