Disagree is related to Protest. Protest is related to Movement. Movement is related to Pass. 
Purchase is a type of Acquisition. Acquisition is a synonym of Learning. Mistake can be used for Learning. 
Disagree <--RelatedTo--> Protest <--RelatedTo--> Movement <--RelatedTo--> Pass 
Purchase --IsA--> Acquisition <--Synonym--> Learning <--UsedFor-- Mistake 