Key is a type of Supply. Theme is a type of Supply. Statement is a type of Theme. Summary is a type of Statement. 
Fiber is related to Hay. Hay is related to Natural. Natural is related to Coal. 
Key --IsA--> Supply <--IsA-- Theme <--IsA-- Statement <--IsA-- Summary 
Fiber <--RelatedTo--> Hay <--RelatedTo--> Natural <--RelatedTo--> Coal 