anchor.diff:      ;
   
   // Not used in the specification (needed here for <uri>).
  -singleLineStringWithoutInterpolation
  +singleStringWithoutInterpolation
       :    RAW_SINGLE_LINE_STRING
  +    |    RAW_MULTI_LINE_STRING
       |    SINGLE_LINE_STRING_DQ_BEGIN_END
       |    SINGLE_LINE_STRING_SQ_BEGIN_END
  +    |    MULTI_LINE_STRING_DQ_BEGIN_END
  +    |    MULTI_LINE_STRING_SQ_BEGIN_END
       ;
   
   singleLineString
  
positive.code: 
  // Not used in the specification (needed here for <uri>).
  stringLiteralWithoutInterpolation
      :    singleLineStringWithoutInterpolation+
      ;
  
  setOrMapLiteral
  
negative.code: 
  // CHANGES:
  //
  // v0.17 Correct `uri` to allow multi-line strings (raw and non-raw).
  //
  // v0.16 (284695f1937c262523a9a11b9084213f889c83e0) Correct instance variable
  // declaration syntax such that `covariant late final` is allowed.
  //
  // v0.15 (6facd6dfdafa2953e8523348220d3129ea884678) Add support for
  // constructor tearoffs and explicitly instantiated function tearoffs and
  // type literals.
  //
  // v0.14 (f65c20124edd9e04f7b3a6f014f40c16f51052f6) Correct `partHeader`
  // to allow uri syntax in a `PART OF` directive.
  //
  // v0.13 (bb5cb79a2fd57d6a480b922bc650d5cd15948753) Introduce non-terminals
  // `builtinIdentifier` and `reservedWord`; update `typeAlias` to enable
  // non-function type aliases; add missing `metadata` to formal parameter
  // declarations; correct `symbolLiteral` to allow `VOID`;
  
  // v0.12 (82403371ac00ddf004be60fa7b705474d2864509) Cf. language issue #1341:
  // correct `metadata`. Change `qualifiedName` such that it only includes the
  // cases with a '.'; the remaining case is added where `qualifiedName` is used.
  