[rules-dev] Justifying favorite colors

Conan and I had a discussion whether the current behavior of drools has a bug or a feature. What do you think? Let's say I have a Person STATED fact: - Person: name=John, favoriteColor=RED - Person: name=Elvis, favoriteColor=GREEN - Person: name=Tom, favoriteColor=GREEN Person has an equals/hashcode based on the name only. I also have a logically asserted ExistingFavoriteColor which just takes a color and has a equals/hashcode based on the color. So now we have a rule which logically asserts all existing favorite colors: rule "favoriteColor" when Person($color : favoriteColor) then insertLogical(new ExistingFavoriteColor($color)); end So if we fire all rules the first time, there will be 2 existing favorite colors: RED and GREEN. Next, John changes his mind, and has a new favoriteColor YELLOW. When all rules are fired, what exisiting favorite colors would you expect? a) YELLOW and GREEN because no one likes RED anymore b) RED, YELLOW and GREEN because John used to like RED -- With kind regards, Geoffrey De Smet