anchor.diff:      ;
   
   subSelect
  -    : selectClause whereClause solutionModifier	-> ^(SUBSELECT whereClause* solutionModifier*)
  +    : selectClause whereClause solutionModifier	-> ^(SUBSELECT selectClause whereClause* solutionModifier*)
       ;
       	
   selectClause
  
positive.code:     ;
      
  groupGraphPatternSub
      : triplesBlock (graphPatternNotTriples DOT? triplesBlock?)* -> triplesBlock (graphPatternNotTriples triplesBlock?)*
      |(graphPatternNotTriples DOT? triplesBlock?)+ -> (graphPatternNotTriples triplesBlock?)+
      ;
  
  triplesBlock
  
negative.code: 
  baseDecl
      : BASE IRI_REF -> ^(BASE IRI_REF)
      ; 
  
  prefixDecl
      : PREFIX PNAME_NS IRI_REF -> ^(PREFIX PNAME_NS IRI_REF)
  