Rule Language:

  Document       ::= IRIMeta? base:IRI? prefixes:Prefix* imports:Import* group:Group?
  Prefix         ::= name:Name iri:IRI
  Import         ::= meta:IRIMeta? iri:IRIConst profile:BasicTerm?
  Group          ::= meta:IRIMeta? groupItems:GroupItem*
  Rule           ::= meta:IRIMeta? vars:Var* conclusion:Conclusion premise:Premise?
  Profile        ::= term:BasicTerm

  GroupItem      ::= Rule | Group
  Rule           ::= ForallRule | ForallFact | PlainRule | PlainFact

  ForallRule     ::= Var* Conclusion Premise
  ForallFact     ::= Var* Conclusion
  PlainRule      ::= Conclusion Premise
  PlainFact      ::= Conclusion

Condition Language:

  Premise        ::= And | Or | Exists | Equal | Member | External | Uniterm | Frame [| Atomic]
  Conclusion     ::= Uniterm | Frame
  Uniterm        ::= op:Const args:BasicTerm*
  Equal          ::= lhs:BasicTerm rhs:Term
  Member         ::= instance:BasicTerm class:BasicTerm
  Frame          ::= subject:BasicTerm slots:Slot*
  Const          ::= TypedConst | ConstShort
  Name           ::= value:String
  Var            ::= name:String
  SymSpace       ::= IRI | Curie

  And            ::= formulas:FORMULA*
  Or             ::= formulas:FORMULA*
  Exists         ::= vars:Var+ formula:FORMULA
  External	 ::= content:Uniterm
  BasicTerm	 ::= Const | Var
  Term           ::= Uniterm | External | Const | Var [| BasicTerm] 
  Slot           ::= predicate:BasicTerm object:BasicTerm
  TypedConst	 ::= value:String type:SymSpace

Annotations:

  IRIMeta       ::= iri:IRIConst? content:IRIMetaContent?
  IRIMetaContent ::= Frame | And