Enroll is derived from Roll. Roll is a synonym of Range. Carry is a type of Range. 
Carry is a type of Range. Carry is a type of Bear. Bear is a type of Seller. 
Enroll --DerivedFrom--> Roll <--Synonym--> Range <--IsA-- Carry 
Range <--IsA-- Carry --IsA--> Bear --IsA--> Seller 