When a model is a tuple <N,E>, where N is node and E is edge. In symbol driven engineering (SDE)  the atomistic symbolic model is a tuple <S>, where S means a symbol. Because there are no edges, the associations or links should be embedded in the symbols. Traversing symbolic model gives interpretations, which can be collected into a compact parse tree or an argumentation tree in order to express model correctness or data flow in the model.

The approach of SDE is rather multidisciplinary. We can compare Symbol with an atom  in chemistry. Science is full of different kinds of symbols. They form different languages and presentations:

See : Sungchal JI. Report: Semiotics of Life: A Unified Theory of Molecular Machines, Cells, the Mind.