This slope console/interpreter is a port of the main Slope interpreter, which is implemented in the Go programming lanuage and is geared more toward CLI tools/programming, with very few web focused features. The goal of porting to JavaScript is to allow more graphical programming, games, and interactive programming that can be distributed easily to non-developers.
The console here is a proof of concept for using the interpreter code (and a way to debug it comfortably). In general, the interpreter is meant to be embedded into other applications. While using this console, it may be helpful to look at the procedure reference on the slope website. Not all procedures referenced in that reference have been implemented and some have slight differences in how they work, but it is the best way to learn for the moment.
To see a list of procedures available to the console, including so-called special forms, run (usage).
(usage)
define
list
assoc
(equal? [1 2] [1 2])
#f
{"key1" "value1" "key2" 22}