Offer is a type of Supply. Special is a type of Offer. Specialty is derived from Special. Specialty is related to Custom. 
Lesson is related to Teaching. Teaching is a type of Doctrine. Doctrine is a type of Belief. 
Supply <--IsA-- Offer <--IsA-- Special <--DerivedFrom-- Specialty <--RelatedTo--> Custom 
Lesson <--RelatedTo--> Teaching --IsA--> Doctrine --IsA--> Belief 