public final CALC expression(String expression) throws ParseException {
        detectImplmentedExtension();
        
        if (infixParser == null)
            infixParser = new InfixParser();
        
        CList infix = infixParser.parse(useExtensions, getProperties(), expression);
        expression(infix, false);
        return getThis();
    }
public final CALC expression ( String expression ) throws ParseException { detectImplmentedExtension ( ) ; if ( infixParser == null ) infixParser = new InfixParser ( ) ; CList infix = infixParser . parse ( useExtensions , getProperties ( ) , expression ) ; expression ( infix , false ) ; return getThis ( ) ; }
Parse and append given expression to existing expression

@param expression
@return
@throws ParseException