Observation is related to See. See is a synonym of Determine. 
Sex is a type of Class. Class is a type of Gathering. Gathering is related to Hall. Hall is a synonym of Mansion. 
Observation <--RelatedTo--> See <--Synonym--> Determine 
Sex --IsA--> Class --IsA--> Gathering <--RelatedTo--> Hall <--Synonym--> Mansion 