Abstract Syntax and Well-formedness for XML Schemas. This exercise is part of a series of three related exercises, see Exercises. You are to find out, say from the Internet, how an XML schema is defined. We refer to [478]. Here is, in any case, our simplified version.

Given the above, or your own version, propose an RSL type definition for XML schemas. Define suitable well-formedness functions. Please comment as to what might be missing from the simplified XML schemas as sketched above and the "real" XML Schemas as reported at.