Sum is a synonym of Heart. Heart is a type of Organ. 
Bed is a type of Put. Arrange is a type of Put. Pair is a type of Arrange. Pair is a type of Occur. 
Sum <--Synonym--> Heart --IsA--> Organ 
Bed --IsA--> Put <--IsA-- Arrange <--IsA-- Pair --IsA--> Occur 