Substantial is related to Important. Important is similar to Historic. Historic is similar to Past. 
Assault is related to Crime. Crime is related to Detective. Detective is a type of Investigator. 
Substantial <--RelatedTo--> Important <--SimilarTo--> Historic <--SimilarTo--> Past 
Assault <--RelatedTo--> Crime <--RelatedTo--> Detective --IsA--> Investigator 