Logical Implication of Structural Integrity Constraints for XML

For tree XML, constraints that specifystructural relationships among nodes or paths are very natural. In this paper, we introduce the concept of structuralintegrity constraints for XML (XSICs), which specify pathimplication, path cooccurrence, path mutual-exclusion, element obligatory inclusion and exclusive inclusion, anddefine the syntax and semantics of XSICs. For reasoning about XSICs, we rewrite all the other constraints intopath implication constraints, and develop a sound and complete set of inference rules for path implication constraints.Meanwhile, we propose the concept of path implication closure. By using the path implication closure, we prove thecompleteness of inference rules, and determine the implication decision about XSICs.