May is related to Request. Request is a type of Ask. Ask is a synonym of Invite. 
Swimming is related to Back. Back is the opposite of Claim. Claim is related to Boast. 
May <--RelatedTo--> Request --IsA--> Ask <--Synonym--> Invite 
Swimming <--RelatedTo--> Back <--Antonym--> Claim <--RelatedTo--> Boast 