Confused with code in rule engine

Hello!

I got confused in the code for combining product categories in the rule engine node. Could you help me anybody?

I try to realise the follow scheme:

If product category = Apparel, then Union_category = Apparel

If product category = Office, then Union_category = Office

If product category = Drinkware, then Union_category =Drinkware

If product category = Lifestyle, then Union_category= Lifestyle

If product category = Bags, then Union_category= Bags

If product category = Headgearl, then Union_category = Apparel

If product category = Notebooks & Journals, then Union_category = Office

Of product category = Waze, then Union_category = Waze

If product category = Bottles, then Union_category =Drinkware

If product category = Acсessories, then Union_category =Acсessories

If product category = Fun, then Union_category =Acсessories

If product category = Gift cards, then Union_category =Gift cards

If product category = Housewares, then Union_category= Lifestyle

If product category = Google, then Union_category =Drinkware

If product category = Backpacks, then Union_category= Bags

Productcategory current, а Unioncategory new