Block is related to Writing. Diary is a type of Writing. 
Severe is a synonym of Terrible. Terrible is the opposite of Beautiful. Beautiful is a synonym of Sunny. Sunny is a different concept from Shade. 
Block <--RelatedTo--> Writing <--IsA-- Diary 
Severe <--Synonym--> Terrible <--Antonym--> Beautiful <--Synonym--> Sunny <--DistinctFrom--> Shade 