Cream is a type of Modify. Cream is related to Addition. Addition is related to Number. 
you are likely to find Fire in/at/on Forest. Fire requires Oxygen. you are likely to find Oxygen in/at/on Water. Water is related to Sail. 
Modify <--IsA-- Cream <--RelatedTo--> Addition <--RelatedTo--> Number 
Forest <--AtLocation-- Fire --HasPrerequisite--> Oxygen --AtLocation--> Water <--RelatedTo--> Sail 