Negation-closure for JSON Schema

JSON Schema is an evolving standard for describing families of documents. It a logical language, based on set assertions that describe features the value under analysis and or structural combinators these assertions, including negation operator. Most languages with enjoy closure: every operator, they have negation-dual allows to be pushed through We show this not case Schema, study how changed latest versions Draft, discuss language may enriched accordingly. To aim, we exploit algebraic reformulation which helpful formal manipulation language.