Add functions to Freedom UI page

Hello Creatio community

I have developed a page using Freedom UI. I want to develop some core functions that i want to call in different Freedom UI screens. For example function calculate as shown below.

define("ApplicationFormSection_FormPage", /**SCHEMA_DEPS*/["@creatio-devkit/common"]/**SCHEMA_DEPS*/, function/**SCHEMA_ARGS*/(sdk)/**SCHEMA_ARGS*/ {
	function calculate(value1, value2) {
		return value1 + value2;
	}
	return {
		viewConfigDiff: /**SCHEMA_VIEW_CONFIG_DIFF*/[..]/**SCHEMA_VIEW_CONFIG_DIFF*/,
		viewModelConfigDiff: /**SCHEMA_VIEW_MODEL_CONFIG_DIFF*/[..]/**SCHEMA_VIEW_MODEL_CONFIG_DIFF*/,
		modelConfigDiff: /**SCHEMA_MODEL_CONFIG_DIFF*/[..]/**SCHEMA_MODEL_CONFIG_DIFF*/,
		handlers: /**SCHEMA_HANDLERS*/[
			{
				request: "crt.HandleViewModelAttributeChangeRequest",
				handler: async (request, next) => {
					if (request.attributeName === "Field1" && !request.silent) {
						var sum = calculate(1, 2);
					}
					return next?.handle(request);
				}
			},
		 ]
	}

This approach doesn't work because every time i change the screen the function is removed automatically. 

Is there a way I can develop some core functions in a different module and call this module inside my "ApplicationFormSection_FormPage" freedom UI page?
Can you give an example for my case?

Best regards