27. A data processing system comprising: means for receiving an input schema including input fields and field values; means for producing at least one set theory expression representing said semantics of said input schema; and, means for transforming said at least one set theory expression into forms that only use AND, OR, and nesting.
27. A data processing system comprising: means for receiving an input schema including input fields and field values; means for producing at least one set theory expression representing said semantics of said input schema; and, means for transforming said at least one set theory expression into forms that only use AND, OR, and nesting. 28. A data processing system according to claim 27 , further comprising: means for transforming said at least one set theory expression, wherein said at least one set theory expression contains at least one subexpression that only uses the AND operator and has no parentheses.