Pretty is related to Handsome. Handsome is the opposite of Ugly. Computer can be Ugly. Computer can be used for Entertainment. 
Afraid is etymologically related to Friend. Afraid is related to Scare. Scare is related to Shock. Shock is related to State. 
Pretty <--RelatedTo--> Handsome <--Antonym--> Ugly <--HasProperty-- Computer --UsedFor--> Entertainment 
Friend <--EtymologicallyRelatedTo-- Afraid <--RelatedTo--> Scare <--RelatedTo--> Shock <--RelatedTo--> State 