Body is related to Foot. you are likely to find Foot in/at/on Boot. Boot is related to Winter. Winter is related to Soup. 
Must is related to Old. Old is related to Length. Length is a type of Extent. 
Body <--RelatedTo--> Foot --AtLocation--> Boot <--RelatedTo--> Winter <--RelatedTo--> Soup 
Must <--RelatedTo--> Old <--RelatedTo--> Length --IsA--> Extent 