FUNCTIONS

A locally defined function can have any number of arguments. All basic
types can be sent in the argument. A return value is sent with the
'return' statement. All four data types can be used in the return statement.
The type of the function must not be declared.

Uninitialized arguments are set to 0.

The type of the argument must not be declared (except for 'static').
It is illegal to have a function with the same name as a global function, or
local variable. Functions are reentrant.

If there is no return statement, the number 0 will be returned.

function_name(argument1, argument2 ...) {
    statements;
    ...
    return value;
}

Functions in other objects can be called with 'call_other(ob, "fun", arg...)'.
This an also be written 'ob->fun(arg...)', which is nicer syntax.

A function can have the type 'static', and it will not be possible to call
with call_other() from another object.