Host requires Plan. Plan is related to Preparation. Preparation is related to Food. Food would make you want to Eat. 
Rock is related to Formation. Secondary is a type of Formation. 
Host --HasPrerequisite--> Plan <--RelatedTo--> Preparation <--RelatedTo--> Food --CausesDesire--> Eat 
Rock <--RelatedTo--> Formation <--IsA-- Secondary 