Participant is related to Person. Dancer is a type of Person. Dancer is related to Singer. 
Old is related to Constitution. Constitution is related to Health. Health is derived from Heal. Therapist can be used for Heal. 
Participant <--RelatedTo--> Person <--IsA-- Dancer <--RelatedTo--> Singer 
Old <--RelatedTo--> Constitution <--RelatedTo--> Health --DerivedFrom--> Heal <--UsedFor-- Therapist 