Dear list, I want to write an application in which the set of widgets in existence, and the subset of them that is displayed, depends on user input. I am using reactive-banana. So far the simplest spec I have imagined for it is this: Initially there is just a text entry box and an empty (hence invisible) collection of labels. The user can do two things: enter the word "add", or enter an integer. Entering the word "add" causes a label to be added to the collection, but not displayed. The labels require no text content. Entering an integer N causes the first N labels to be displayed onscreen. The text entry box remains visible. I am totally baffled. In particular, the Behavior paradigm, though it is elegant and beautiful whenever I study it, I have no idea how to apply. Thank you, Jeff