Script functions are declared at the top-level of a script, not inside a class definition. Script functions are visible throughout the entire script -- a member access expression is not needed.

function square(x : Number) : Number { x * x }
println( square(7) )

If access modifiers are added which make the script function visible outside the script, they may be accessed as members of the script. For example, if this is script Foo.fx:

public function square(x : Number) : Number { x * x }

Then script Bar.fx can access square:

println(Foo.square(10))

Instance functions are declared at the top-level of a class. Instance functions are visible through-out the entire script -- a member access expression is not needed within the class (or its subclasses) but is needed outside of the class.

class Scale { 
   var factor : Number; 
   function transform(x : Number) : Number { factor * x } 
} 
var tf = Scale { factor: 25.0 } 
println(tf.transform(10.0))