Opponent is a synonym of Opposition. Opposition is a type of Relation. Relation is related to Daughter. 
Support is related to Structure. Structure is related to Mountain. Mountain is related to Peak. 
Opponent <--Synonym--> Opposition --IsA--> Relation <--RelatedTo--> Daughter 
Support <--RelatedTo--> Structure <--RelatedTo--> Mountain <--RelatedTo--> Peak 