It depends on how your functions are defined. If they are defined as global definitions in a library then you just have to make sure the name is capitalized and that you are spelling it correctly.
If the function is dynamically defined, you need to keep in mind that functions do not have closure like blocks do in Suneido so you can’t do something like:
a = function() { }
b = function() { a() }
b()
If this does not answer your question, consider posting an example of what you are trying to do.