Variables are declared using
define-global. Variables declared with
define are available for use anywhere in subsequent expressions in the same scope, and
define-global makes them globally available.
do evaluates multiple expressions, and itself evaluates to the value of the last expression.
Variables for a limited scope are introduced using
You can see that
let accepts a list of names and values, called bindings, or it can work with a single binding. More than one expression can follow the bindings, which works like
Variables and list values can be updated using
set, which evaluates to the value that it updated: