java.lang.StringIndexOutOfBoundsException: String index out of range: -1
	at java.lang.String.substring(String.java:1911)
	at org.drools.core.rule.constraint.MvelConstraint.getLeftInExpression(MvelConstraint.java:570)
	at org.drools.core.rule.constraint.MvelConstraint.equals(MvelConstraint.java:621)
	at org.drools.core.reteoo.AlphaNode.internalEquals(AlphaNode.java:200)
	at org.drools.core.common.BaseNode.thisNodeEquals(BaseNode.java:193)
	at org.drools.core.reteoo.SingleObjectSinkAdapter.getMatchingNode(SingleObjectSinkAdapter.java:136)
	at org.drools.core.reteoo.builder.BuildUtils.attachNode(BuildUtils.java:120)
	at org.drools.core.reteoo.builder.PatternBuilder.buildAlphaNodeChain(PatternBuilder.java:331)
	at org.drools.core.reteoo.builder.PatternBuilder.attachAlphaNodes(PatternBuilder.java:312)
	at org.drools.core.reteoo.builder.PatternBuilder.attachPattern(PatternBuilder.java:129)
	at org.drools.core.reteoo.builder.PatternBuilder.build(PatternBuilder.java:77)
	at org.drools.core.reteoo.builder.GroupElementBuilder$AndBuilder.build(GroupElementBuilder.java:108)
	at org.drools.core.reteoo.builder.GroupElementBuilder.build(GroupElementBuilder.java:68)
	at org.drools.core.reteoo.builder.ReteooRuleBuilder.addSubRule(ReteooRuleBuilder.java:161)
	at org.drools.core.reteoo.builder.ReteooRuleBuilder.addRule(ReteooRuleBuilder.java:133)
	at org.drools.core.reteoo.ReteooBuilder.addRule(ReteooBuilder.java:106)
	at org.drools.core.impl.KnowledgeBaseImpl.addRule(KnowledgeBaseImpl.java:1586)
	at org.drools.core.impl.KnowledgeBaseImpl.addRule(KnowledgeBaseImpl.java:1566)
	at org.drools.core.impl.KnowledgeBaseImpl.internalAddPackages(KnowledgeBaseImpl.java:939)
	at org.drools.core.impl.KnowledgeBaseImpl.access$000(KnowledgeBaseImpl.java:119)
	at org.drools.core.impl.KnowledgeBaseImpl$1.run(KnowledgeBaseImpl.java:727)
	at org.drools.core.impl.KnowledgeBaseImpl.enqueueModification(KnowledgeBaseImpl.java:735)
	at org.drools.core.impl.KnowledgeBaseImpl.addPackages(KnowledgeBaseImpl.java:724)
	at org.drools.core.impl.KnowledgeBaseImpl.addKnowledgePackages(KnowledgeBaseImpl.java:284)
	at org.drools.compiler.kie.builder.impl.KieContainerImpl.createKieBase(KieContainerImpl.java:590)
	at org.drools.compiler.kie.builder.impl.KieContainerImpl.getKieBase(KieContainerImpl.java:524)
	at org.drools.compiler.kie.builder.impl.KieContainerImpl.newKieSession(KieContainerImpl.java:687)
	at org.drools.compiler.kie.builder.impl.KieContainerImpl.newKieSession(KieContainerImpl.java:629)
	at org.drools.compiler.kie.builder.impl.KieContainerImpl.newKieSession(KieContainerImpl.java:611)
	at com.sample.DroolsTest.main(DroolsTest.java:56)