This is the Skyline schema module of FLD. It is split off from the Baseline schema for modularity. The Skyline XML schema is based on the following EBNF (which adds Group and Document, and brings 'Implies' into FORMULA and TERMULA): Document ::= IRIMETA? 'Document' '(' Dialect? Base? Prefix* Import* Module* Group? ')' Dialect ::= 'Dialect' '(' Name ')' Base ::= 'Base' '(' ANGLEBRACKIRI ')' Prefix ::= 'Prefix' '(' Name ANGLEBRACKIRI ')' Import ::= IRIMETA? 'Import' '(' LOCATOR PROFILE? ')' Module ::= IRIMETA? 'Module' '(' (Const | Expr) LOCATOR ')' Group ::= IRIMETA? 'Group' '(' (FORMULA | Group)* ')' Implies ::= IRIMETA? FORMULA ':-' FORMULA FORMULA ::= Implies | IRIMETA? CONNECTIVE '(' FORMULA* ')' | IRIMETA? QUANTIFIER '(' FORMULA ')' | IRIMETA? 'Neg' FORMULA | IRIMETA? 'Naf' FORMULA | IRIMETA? FORMULA '@' MODULEREF | FORM TERMULA ::= Implies | IRIMETA? CONNECTIVE '(' TERMULA* ')' | IRIMETA? QUANTIFIER '(' TERMULA ')' | IRIMETA? 'Neg' TERMULA | IRIMETA? 'Naf' TERMULA | IRIMETA? TERMULA '@' MODULEREF | TERM PROFILE ::= ANGLEBRACKIRI Note that this is an extension of the syntax for the Baseline schema (FLDBaseline.xsd).