Spend is related to Budget. Budget is related to Planning. 
you are likely to find Body in/at/on Grave. you are likely to find Body in/at/on Bag. Envelope is a type of Bag. Envelope is related to Invitation. 
Spend <--RelatedTo--> Budget <--RelatedTo--> Planning 
Grave <--AtLocation-- Body --AtLocation--> Bag <--IsA-- Envelope <--RelatedTo--> Invitation 