Hello Alin, I have run your code on my computer and it works: 1. (deftemplate person(slot name)(slot age)) (my question is why did you create your template if later create a class I dont understand but this is not a mistake) 2. (defclass P(is-a :THING)(slot name(type string))(slot age(type integer))) 3. (make-instance of P(name "John")(age 30)) 4. (mapclass P) 5. (facts) (now I see your instance created in Protege) I work with Protege 3.3, Jesstab 1.6 and Jess 7.01p1. I know that it is a new version of jesstab 7.102, but I didn't tested very well. What do you exactly want to do? Ana p.s. are you from romania?
