Structure is relationship. The structure of space-time must therefore be made up of relationships between whatever it is that composes reality. Space-time exists, and can then most generally be said to be composed of existence. The relationships which make up the structure of space-time must therefore be relationships existence has formed with itself, since there is nothing else. The structure of space-time can therefore be modeled in terms of relationships existence has formed with itself.
Existence can form a relationships with itself by dualizing into a pair of relative realities.
Existence can form multiple relational levels of reality by successively dualizing, by repetitively and progressively existing in relation to itself. The process of successive dualization of existence creates a relational structure, called a relational matrix, that is composed of individual units of relative existence called reality cells.