The user interface of ft has a Prolog feel to it. Comment brackets are nestable.
Output is always to stdout.
In connection with input from or to files, see echo, read below. An EOF from stdin is equivalent to quit. The command set alone gives the current values of the alterable system variables. 60,echo 1. reset The system variables are reset to their boot values. The main stack, the formula stack, and the save areas are resized to their initial values.