Hi, I need a container data structure for storing anonymous objects - most likely things that have not value such as STM (), but probably other things as well. This will allow me to later on, iterate over the container and process those objects. Additionally I have the requirement that I need to be able to remove individual objects from this container. It needs to be linear time. main = do container <- nil key1 <- cons 1 container key2 <- cons 2 container key3 <- cons 3 container key4 <- cons 4 container key5 <- cons 5 container unlink key3 container unlink key2 container unlink key4 container list <- toList container putStrLn (show list) The above should give: [1, 5] What should I use? Thanks -John