I'm a beginner, I'd like someone to help me understand a few lines of code My questions are: 1) Maybe String is an application of the constructor Maybe to the type String. What does it mean? Is there anything equivalent in the C language? 2) Is this a function with three arguments? type T = [Char] type P = (Char, Maybe String) type Delta = ((Maybe Char, Char), Maybe String) fromGtoM :: T -> [P] -> [Delta] 3) is this a usage of the above mentioned function? fromGtoM t p = terminalRules ++ varRules I dont'see why the function has three arguments but then only two are used t p. 4) what does ++ mean ? Sorry, for posting too many questions. Thanks in advance. -- moowoo9@fastmail.fm -- http://www.fastmail.fm - Access your email from home and the web