Thanks Michael for the immediate response.
 
Yes.The rule has been defined in guided web editor.
 
I had taken sample respoitory ( Pricing Loan guided web editor rules) and added the negate option in the row-1 of the rules and Validating the rules throws the error posted earlier.
 
Here is the source of the rule-1 ,
 
1. | #from row number: 1
2. | rule "Row 1 Pricing loans"
3. |     dialect "mvel"
4. |     when
5. |         not (
6. |             application : LoanApplication( amount > "131000" , amount <= "200000" , lengthYears == "30" , deposit < "20000" )
7. |             income : IncomeSource( type == "Asset" )
8. |         )
9. |     then
10. |         application.setApproved( true );
11. |         application.setInsuranceCost( 0 );
12. |         application.setApprovedRate( 2 );
13. | end
 
Regards,
Mahmood
From: mahmood lebbai <mahmoodlebbai@yahoo.com>
To: "rules-users@lists.jboss.org" <rules-users@lists.jboss.org>
Sent: Saturday, 21 May 2011 2:55 PM
Subject: DROOLS Negate Question
I need help to clarify the following
I had taken latest Guvnour 5.2.0 M2 version and use the sample pricing loan rules.
When i tried to use the "Negate" Meta data option and set it to true on first rule , i had got the following error.
Pricing loans] [ERR 102] Line 7:3 mismatched input 'income' in rule "Row 1 Pricing loans"
[Pricing loans] Line 16:0 unexpected exception at input 'rule'. Exception: java.util.EmptyStackException. Stack trace: java.util.EmptyStackException at java.util.Stack.peek(Stack.java:79) at java.util.Stack.pop(Stack.java:61) at org.drools.lang.ParserHelper.popParaphrases(ParserHelper.java:409) at org.drools.lang.ParserHelper.end(ParserHelper.java:723) at org.drools.lang.DRLParser.rule(DRLParser.java:915) at org.drools.lang.DRLParser.statement(DRLParser.java:248) at org.drools.lang.DRLParser.compilationUnit(DRLParser.java:143) at org.drools.compiler.DrlParser.compile(DrlParser.java:225) at org.drools.compiler.DrlParser.parse(DrlParser.java:71) at org.drools.compiler.DrlParser.parse(DrlParser.java:76) at 
I have a similar requirement where in I need to write both negate with true and false within the same ruleset in guvnour. Please help me out how to achieve this.
Regards,
Mahmood