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 <<>>
Reply-To: <<>>
Date: Wed, 11 Jan 2012 14:38:31 -0500
To: <<>>
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?

Hunter McMillen

Reply via email to