Two windows in the buffer
- Program history, with most recent information at the top and oldest at the bottom.
- Evaluation area showing current expression and the values of "current"
variables. New expressions can be evaluated, but you shouldn't "alter the state"
of the computation.
- Useful commands: C-N, C-P go up and down the history; p allows the
computation to continue in many cases; e shows more details of the values of
variables.