Abstract: A data management method for representing hierarchical functional dependencies. Data are modeled as assertions assigning values to attributes along a path of dependencies. Attributes are created by specifying their parents and are assigned identifiers which distinguish them from their siblings. Assertions are stored as storage sequences, which are identifiers corresponding to the attributes of a path alternating with values assigned to the attributes. Storage sequences are stored as indices of a hierarchical data structure. Application values are stored in the tree with predecessors, and deleted with dependents. Assertions are denoted by function assignments which assign values to function instances. Function instances may reference multiple values, and attributes may be created at any time. Data storage, access and deletion are efficient.