anchor.diff:    ;
   //[4]
   ForExpr
  -  : SimpleForClause 'return' ExprSingle
  +  : SimpleForClause RETURN ExprSingle
     ;
   //[5]
   SimpleForClause
  -  : 'for' '$' VarName 'in' ExprSingle (',' '$' VarName 'in' ExprSingle)*
  +  : FOR '$' VarName IN ExprSingle (',' '$' VarName IN ExprSingle)*
     ;
   //[6]
   QuantifiedExpr
  -  : ('some' | 'every') '$' VarName 'in' ExprSingle (',' '$' VarName 'in' ExprSingle)* 'satisfies' ExprSingle
  +  : (SOME | EVERY) '$' VarName IN ExprSingle (',' '$' VarName IN ExprSingle)* SATISFIES ExprSingle
     ;
   //[7]
   IfExpr
  -  : 'if' '(' Expr ')' 'then' ExprSingle 'else' ExprSingle
  +  : IF '(' Expr ')' THEN ExprSingle ELSE ExprSingle
     ;
   //[8]
   OrExpr
  -  : AndExpr ( 'or' AndExpr )*
  +  : AndExpr ( OR AndExpr )*
     ;
   //[9]
   AndExpr
  -  : ComparisonExpr ( 'and' ComparisonExpr )*
  +  : ComparisonExpr ( AND ComparisonExpr )*
     ;
   //[10]
   ComparisonExpr
  
positive.code:   ;
  //[50]
  SequenceType
    : ('empty-sequence' '(' ')')
    | (ItemType OccurrenceIndicator?)
    ;
  //[51]
  
negative.code:   ;
  //[66]
  SchemaElementTest
    : SCHEMA_ELEMENT '(' ElementDeclaration ')'
    ;
  //[67]
  ElementDeclaration
  