As we said before, there exist special variables called parameters that exist in all scopes. To declare a parameter called foo with the initial value 1, we write

parameter foo = 1

From then on, foo is a strictly global variable. Setting foo inside any function will modify the variable in all contexts, that is, functions do not have a private copy of parameters.

When you undefine a parameter using the undefine function, it stops being a parameter.

Some parameters are built-in and modify the behavior of genius.