Rail is a type of Fish. Fish is a type of Animal. 
Wound is the opposite of Heal. Therapist can be used for Heal. Therapist is a type of Expert. Investigator is a type of Expert. 
Rail --IsA--> Fish --IsA--> Animal 
Wound <--Antonym--> Heal <--UsedFor-- Therapist --IsA--> Expert <--IsA-- Investigator 