Solar is related to Energy. Energy is the opposite of Weakness. Weakness is the opposite of Force. Enforce is derived from Force. 
Border is a synonym of Edge. Edge is related to Upper. Upper is related to Advantage. Advantage is a type of Asset. 
Solar <--RelatedTo--> Energy <--Antonym--> Weakness <--Antonym--> Force <--DerivedFrom-- Enforce 
Border <--Synonym--> Edge <--RelatedTo--> Upper <--RelatedTo--> Advantage --IsA--> Asset 