Finger can be used for Warn. Warn is a synonym of Discourage. Discourage is the opposite of Encourage. 
Edge is related to Stop. Stop is a type of End. End is the opposite of Start. Start is related to Left. 
Finger --UsedFor--> Warn <--Synonym--> Discourage <--Antonym--> Encourage 
Edge <--RelatedTo--> Stop --IsA--> End <--Antonym--> Start <--RelatedTo--> Left 