Country is related to Map. Travel requires Map. Travel is related to Transport. 
Mansion is related to House. you are likely to find Machine in/at/on House. Machine is related to Plane. 
Country <--RelatedTo--> Map <--HasPrerequisite-- Travel <--RelatedTo--> Transport 
Mansion <--RelatedTo--> House <--AtLocation-- Machine <--RelatedTo--> Plane 