Nuprl
is implemented in Lisp as a function; therefore, entering the
Nuprl
environment entails first invoking Lisp. Currently there are two
implementations, one running on a
Symbolics Lisp Machine and one written in
Franz Lisp and running on Unix. One invokes
the Nuprl
environment using
commands which load the system in the appropriate Lisp environment.
The system comes up with a two--window display as in figure 
.
P> is the top--level prompt from the command module. Depending on its mode, the window may display one of several prompts The modes and their corresponding prompts are:
