Hi Mark, Few questions to confirm with you, or anyone else who are familiar with MVEL's design? 1) What is the design intention to not returning ExecutableStatement when trying to compile an expression? 2) How the 'Safe' interface is being used? Why MVEL has both ExecutableAccessorSafe and ExecutableAccessor? Which one should be used? 3) What is the major differences between ASTNode.getReducedValueAccelerated and getReducedValue? 4) What is the major purpose of debugSymbols? (looks like it has to be used with a source file specified?) ----- Ivan, your Panda, forever -- View this message in context: http://drools.46999.n3.nabble.com/MVEL-why-compileExpression-returns-Seri... Sent from the Drools: User forum mailing list archive at Nabble.com.