Fly is related to Fishing. Pond can be used for Fishing. Pond is related to Water. you are likely to find Bottom in/at/on Water. 
Inventory is related to Warehouse. Warehouse is related to Factory. you are likely to find Factory in/at/on City. City is related to Central. 
Fly <--RelatedTo--> Fishing <--UsedFor-- Pond <--RelatedTo--> Water <--AtLocation-- Bottom 
Inventory <--RelatedTo--> Warehouse <--RelatedTo--> Factory --AtLocation--> City <--RelatedTo--> Central 