<\body> Several other features are supported in order to write interfaces between and extern applications. Some of these are very hairy or quite specific. Let us briefly describe a few miscellaneous features: The ``stop'' icon can be used in order to interrupt the evaluation of some input. When pressing this button, will just send a signal to your application. It expects your application to finish the output as usual. In particular, you should close all open -blocks. Some systems start a multiline input mode as soon as you start to define a function or when you enter an opening bracket without a matching closing bracket. allows your application to implement a special predicate for testing whether the input is complete. First of all, this requires you to specify the configuration option <\scheme-fragment> (:test-input-done #t) As soon as you will press in your input, will then send the command <\quotation> <\framed-fragment> <\verbatim> (input-done? ) Your application should reply with a message of the form <\quotation> <\framed-fragment> scheme:> where > is either or . The plug-in provides an example of this mechanism (see in particular the file ). <\initial> <\collection>