Explain is a type of State. State is a synonym of Accident. Accident is related to Claim. Proclaim is etymologically related to Claim. 
Reason is a type of Explanation. 
Explain --IsA--> State <--Synonym--> Accident <--RelatedTo--> Claim <--EtymologicallyRelatedTo-- Proclaim 
Reason --IsA--> Explanation 