REGEXP_FILE
  RegExpPatternImpl: <\p{^L}>
    RegExpBranchImpl: <\p{^L}>
      RegExpPropertyImpl: <\p{^L}>
        PsiElement(PROPERTY)('\p')
        PsiElement(LBRACE)('{')
        PsiErrorElement:Negating a property not allowed in this regular expression dialect
          <empty list>
        PsiElement(CARET)('^')
        PsiElement(NAME)('L')
        PsiElement(RBRACE)('}')