والإضافة: هي عبارة عن النسبة المكررة.
Relation is a repeated or reciprocal reference: when a relation is considered from one side, a corresponding relation can be conceived from the other.
Father is understood relative to a child, and child relative to a parent. Teacher and student can likewise illustrate relation.
The point is not that two things merely occupy one place. Rather, each is understood by reference to the other within the relevant relational description.