Structural Stability of Information

This paper defines structural stability as a system-level property in the Modal-Dependence Calculus. Stability is characterized by the invariance of the evaluation state of a structure under admissible transformations. A structure is stable if and only if every admissible transformation preserves its evaluation state, while any mismatch between the original and transformed states indicates instability. The analysis shows that stability is fully determined by element-level definability and is equivalent to structural admissibility. This establishes stability as a binary condition independent of structural size, ordering, or transformation, and provides a formal criterion for identifying persistence across mappings.