The asterisks are part of the defglobal's name. You're not comparing to the defglobal: you're binding the value in the slot to a new variable. It's not legal to negate such a constraint in its first use, as the error message said. You need to use
(unit (ID ?id) (typeID ?typeID) (player ~?*PLAYER_ID*)) From: Hunter McMillen <mcmil...@gmail.com<mailto:mcmil...@gmail.com>> Reply-To: <jess-users@sandia.gov<mailto:jess-users@sandia.gov>> Date: Wed, 11 Jan 2012 14:38:31 -0500 To: <jess-users@sandia.gov<mailto:jess-users@sandia.gov>> Subject: JESS: [EXTERNAL] How to negate a variable when in lhs of a rule Hi everyone, I am trying to differentiate between Objects that belong to a certain user inside two of my rules. I have a variable created from Java like this: engine.getGlobalContext().setVariable("PLAYER_ID", new Value(player.getID()); And I want to use this variable in rules to determine which objects belong to each player. This rule works fine when just using ?PLAYER_ID (defrule myUnitSeen (unit (ID ?id) (typeID ?typeID) (player ?PLAYER_ID)) => .....) But when I try to negate the variable I get an error, "First use of variable negated: PLAYER_ID" (defrule enemyUnitSeen (unit (ID ?id) (typeID ?typeID) (player ~?PLAYER_ID)) => .....) How can I specify anything other than ?PLAYER_ID on the lhs of a rule? Thanks, Hunter McMillen
