External is related to Door. you are likely to find Door in/at/on Classroom. you are likely to find Notebook in/at/on Classroom. you are likely to find Notebook in/at/on Office. 
Walk is related to Swim. Swim is related to Part. 
External <--RelatedTo--> Door --AtLocation--> Classroom <--AtLocation-- Notebook --AtLocation--> Office 
Walk <--RelatedTo--> Swim <--RelatedTo--> Part 