Stage is related to Actor. Plant is a type of Actor. Fruit is created by Plant. Fruit is related to Tomato. 
Example is related to Disease. Infection is a type of Disease. Virus can cause/lead to Infection. 
Stage <--RelatedTo--> Actor <--IsA-- Plant <--CreatedBy-- Fruit <--RelatedTo--> Tomato 
Example <--RelatedTo--> Disease <--IsA-- Infection <--Causes-- Virus 