Formal is similar to Logical. Logical is a synonym of Legitimate. Legitimate is similar to Valid. Valid is related to True. 
Mother is related to Come. Come is a type of Experience. 
Formal <--SimilarTo--> Logical <--Synonym--> Legitimate <--SimilarTo--> Valid <--RelatedTo--> True 
Mother <--RelatedTo--> Come --IsA--> Experience 