Proof is a type of Impression. Image is a type of Impression. Image is a synonym of Counterpart. 
Unusual is a synonym of Weird. Weird is etymologically related to Worth. Worth is related to Merit. Merit is related to Credit. 
Proof --IsA--> Impression <--IsA-- Image <--Synonym--> Counterpart 
Unusual <--Synonym--> Weird --EtymologicallyRelatedTo--> Worth <--RelatedTo--> Merit <--RelatedTo--> Credit 