Theoretical is related to Ideal. Ideal is related to Good. Good is related to Egg. 
Piece can be used for Puzzle. Piece is related to Head. Head is related to Chicken. 
Theoretical <--RelatedTo--> Ideal <--RelatedTo--> Good <--RelatedTo--> Egg 
Puzzle <--UsedFor-- Piece <--RelatedTo--> Head <--RelatedTo--> Chicken 