On 15.12.2010 10:01, Diego San Esteban wrote:

Greetings,
 
How is it possible to implement a "rollback" in the KB?

Suppose that when retracting a fact, I want to undo the changes made.
  

A very simple, yet effective solution would be to exclusively use insertLogical(). No updates to facts which are already asserted, no normal "insert".

Best regards

Ansgar