The semantic rule engine: business rules written over semantic paths rather than over the XPath of a syntax, so that one rule serves a UBL invoice, a CII invoice and a document that was never XML alike. A rule is declarative JSON over a closed operator set, or a Java class where the language does not reach; both kinds live in one rule pack and produce the same findings. The findings are a layer of their own and are never presented as conformance to the ESJ format.