Miscellaneous Operator Documentation.

The `show' command will show a definition of some kind, or object pointed at. `(cm-(mouseright))' will do this wherever you click.

The `(c-a)(c-?)' command will glean information from the system about the point-term; mostly about the operator. `(cm-(mousemiddle))' will do this wherever you click.
It will give you a pointer to the ABS and DISP objects for the point-term, and perhaps comments taken from those objects.
It will tell you if the toggling commands `(backspace)' and `(c-a)(c-(backspace))' have any effect, and describe the effects of toggling terms like it. doc for toggling
It will also list commands that probably insert the operator.
If the point-term is a (cached) global ML-id, then this will be mentioned, and if an appropriate comment can be gleaned from the definition, it will be shown.
If the point-term is an edit command, then it will also be "reviewed" (see below).

Button Documentation.

Edit buttons are used by clicking on them with `(mouseleft)'. There are a few special purpose buttons, but most buttons either view an object, or insert a term, or invoke ML (usually on the point).
There is an edit button, Buttons, which you will also find in MainMenu, that will scan the point term for edit buttons and pop up a window revealing them, and any documentation it could glean from the system.

Here are some edit buttons you should see in MainMenu to help find documentation; try the Buttons button on them:

Buttons CmdReview HowTo?

Edit Command Documentation.

Commands are usually displayed in a way that shows what you need to key in to invoke it. For example, here is a command that will move the point up to the parent: `(m-k)'. For
You can get a "review" of a command by using the `show' command on it. To review all commands, or a special class of them, use the CmdReview button which you can find in MainMenu. doc for edit cmd review
You can also get a review of a command keying in the command string immediately preceded by `(m-q)'.

Hypothetical Execution Documentation.

Many commands are rather generic, but are tailored for special behavior in different circumstances. For some of these there is a "hypothetical" version that simply advises the user in the LISP window as to what action would occur.

hypothetical	`(mouseleft)'	is	`(cm-(mouseleft))'
hypothetical	`(c-z)'	is	`{(c-n)(m-n)}(c-z)'
hypothetical	`(c-d)'	is	`{(c-n)(m-n)}(c-d)'

ML Documentation (including Tactics). doc for ml doc

WWW page for Nuprl:

http://www.nuprl.org