While I am reading TypeCompose module, I am having trouble finding where ~> comes from? (And its son ~~> and grandson ~~~>, etc.) This is my immediate question. Help is appreciated. A bigger (higher-order?) issue I encountered and I think other people could also have is to look up all these special "symbols" during the learning curve. As things are getting higher and higher order in Haskell, more inventive symbols are appearing. It becomes harder to remember the exact definitions are. The difficulties are: 1) I used to see a page on haskell.org that lists many symbols, but I could not find that page any more. 2) You would hope there is a quick way to search those symbols. But most search engines do not treate symbols friendly, often just ignore them. I typed ~> in Hoogle, it also returned nothing. 3) If the module defining the symbol is not in standard library, it is not possible to look up the symbol in the core library index. The only way to find the symbol seems to go to the source code, check every module being imported and if I am lucky I will find it in the same package. If I am not lucky, I will have to search that module on the Internet, and hunt it down recursively. I wonder if anybody has the same problem. If enough crowd have the same problem, maybe there could be a better way to handle this kind of documentation/learning issue! Thanks, Steve