Basis is related to Price. Price is related to Reduction. Reduction is a synonym of Decrease. Decrease is a synonym of Reduce. 
Settle is a synonym of Regulate. Zone is a type of Regulate. Zone is a type of Structure. 
Basis <--RelatedTo--> Price <--RelatedTo--> Reduction <--Synonym--> Decrease <--Synonym--> Reduce 
Settle <--Synonym--> Regulate <--IsA-- Zone --IsA--> Structure 