Spare is related to Flat. Flat is related to Paper. Paper is a type of Invention. 
Pain is a type of Feeling. Thing is a type of Feeling. Thing is related to Sock. Sock is related to Provider. 
Spare <--RelatedTo--> Flat <--RelatedTo--> Paper --IsA--> Invention 
Pain --IsA--> Feeling <--IsA-- Thing <--RelatedTo--> Sock <--RelatedTo--> Provider 