The short answer is "no". Templates are like Java classes, and so this is akin to asking if you can write Java code that reads the value of a "score" member variable in any class.
But you can use template inheritance to achieve your goal. Templates can extend other templates; just put your "score" slot in a base template, and extend everything else that needs a "score" slot from that common base, and write your patterns to match the base template. Read about the use of "extends" in templates here: http://www.jessrules.com/jess/docs/71/memory.html From: owner-jess-us...@sandia.gov [mailto:owner-jess-us...@sandia.gov] On Behalf Of Aurelien Mazurie Sent: Friday, July 26, 2013 4:43 PM To: jess-users Subject: JESS: [EXTERNAL] Matching facts based on a slot, but not the fact's type Dear Jess users, I am still learning the ropes, and cannot find an answer to the following question either online or in the 'Jess in action' book. Is there a way to match facts in a LHS based on the presence of a slot? For example, I have two templates: (deftemplate A (slot score)) (deftemplate B (slot score)) I would like my rule to be triggered if any fact (either from template A, B, or others) have a 'score' slot with a specific value. For now I can do it by manually adding references to A and B in the LHS, but this will not scale well. I'm looking for a solution that can just work on any fact, regardless of the template they are defined from. Best, Aurelien