NEMO programs are generally not interactive, they are of the so-called ``load-and-go'' type, i.e. at startup all necessary parameters are supplied either through the commandline, or, as will be described later, a keyword file or even a combination thereof. The actual program is then started until it's all done. There is no feedback possible to the user. This is particularly convenient when combining programs into a script or batch type environments.
There are of course a few exceptions. Certain graphics interfaces require the user to push a button on the keyboard or click the mouse to advance to a next frame or something like that; a few very old NEMO programs may still get their input through user defined routines (they will become obsolete).
Depending on how the user interface on your system has been compiled, NEMO programs can be interrupted2.6 to go into the REVIEW section during, or even optionally at the start of the execution of the program. The program pauses here for user interaction.
The REVIEW» prompt appears and the user can interact with the program and reset keywords. The program can also be continued or gracefully aborted, and other programs can be run in the mean time. In Appendix an overview of all the commands and their options are given in more detail.
It should be remarked though that the program must be written in a certain way that resetting the value of the keyword also affects the actual flow of the program. Although this is always true for the system keywords (help, yapp, debug etc.), it is not guaranteed2.7 for the program defined keywords (the ones you see when the help= keyword is used). The documentation should explain how to handle such situations, however in most current situations modifying a program keyword will not affect the flow of the program. A good example would be a program that iterates, and is given a new tolerance criterion or new initial conditions.
The REVIEW section is mostly useful to interrupt a quiet program that seems to take to long, and increase the debug level.