Wall can be used for Privacy. Curtain can be used for Privacy. Curtain is a type of Supply. Supply is related to Cost. 
Bullet is related to Nut. Nut is a type of Gather. 
Wall --UsedFor--> Privacy <--UsedFor-- Curtain --IsA--> Supply <--RelatedTo--> Cost 
Bullet <--RelatedTo--> Nut --IsA--> Gather 