Musical is similar to Liquid. Liquid is a synonym of Fluid. Fluid is a synonym of Mobile. 
Topic is related to Mathematics. Mathematics is related to Discipline. Discipline is a type of Trait. 
Musical <--SimilarTo--> Liquid <--Synonym--> Fluid <--Synonym--> Mobile 
Topic <--RelatedTo--> Mathematics <--RelatedTo--> Discipline --IsA--> Trait 