org.jbpm.process.instance.impl
Interfaces 
Action
AssignmentAction
ConstraintEvaluator
ContextInstanceFactory
ReturnValueEvaluator
Classes 
ContextInstanceFactoryRegistry
DefaultProcessInstanceManager
DefaultProcessInstanceManagerFactory
MVELAction
MVELReturnValueEvaluator
ProcessInstanceImpl
ReturnValueConstraintEvaluator
RuleConstraintEvaluator
XPATHReturnValueEvaluator