Casualty is a type of Decrease. Break is a type of Decrease. Break is the opposite of Working. 
Boss is similar to Manager. you are likely to find Manager in/at/on Meeting. Meeting is related to Corner. 
Casualty --IsA--> Decrease <--IsA-- Break <--Antonym--> Working 
Boss <--SimilarTo--> Manager --AtLocation--> Meeting <--RelatedTo--> Corner 