Seed is related to Crop. Crop is related to Corn. Corn is related to Agriculture. 
Cart is related to Vehicle. Glass is a type of Vehicle. Glass is part of Window. Window is related to Entrance. 
Seed <--RelatedTo--> Crop <--RelatedTo--> Corn <--RelatedTo--> Agriculture 
Cart <--RelatedTo--> Vehicle <--IsA-- Glass --PartOf--> Window <--RelatedTo--> Entrance 