SHELL_SCRIPT
  COMMANDS_LIST
    COMMAND_SUBSTITUTION_COMMAND
      PsiElement(OPEN_BACKQUOTE)('`')
      COMPOUND_LIST
        GENERIC_COMMAND_DIRECTIVE
          LITERAL
            PsiElement(word)('echo')
      PsiElement(CLOSE_BACKQUOTE)('`')
  PsiElement(\n)('\n')
  COMMANDS_LIST
    COMMAND_SUBSTITUTION_COMMAND
      PsiElement(OPEN_BACKQUOTE)('`')
      COMPOUND_LIST
        SIMPLE_COMMAND
          GENERIC_COMMAND_DIRECTIVE
            LITERAL
              PsiElement(word)('echo')
          PsiWhiteSpace(' ')
          LITERAL
            PsiElement(word)('a')
      PsiElement(CLOSE_BACKQUOTE)('`')
  PsiElement(\n)('\n')
  COMMANDS_LIST
    COMMAND_SUBSTITUTION_COMMAND
      PsiElement(OPEN_BACKQUOTE)('`')
      COMPOUND_LIST
        GENERIC_COMMAND_DIRECTIVE
          LITERAL
            PsiElement(word)('echo')
      PsiElement(CLOSE_BACKQUOTE)('`')
  PsiElement(\n)('\n')
  COMMANDS_LIST
    COMMAND_SUBSTITUTION_COMMAND
      PsiElement(OPEN_BACKQUOTE)('`')
      PsiElement(CLOSE_BACKQUOTE)('`')
  PsiElement(\n)('\n')
  COMMANDS_LIST
    COMMAND_SUBSTITUTION_COMMAND
      PsiElement(OPEN_BACKQUOTE)('`')
      COMPOUND_LIST
        SIMPLE_COMMAND
          GENERIC_COMMAND_DIRECTIVE
            LITERAL
              PsiElement(word)('echo')
          PsiWhiteSpace(' ')
          SIMPLE_COMMAND_ELEMENT
            PsiElement($)('$')
            ARITHMETIC_EXPANSION
              PsiElement(()('(')
              PsiElement(()('(')
              LITERAL_EXPRESSION
                NUMBER
                  PsiElement(int)('1')
              PsiElement())(')')
              PsiElement())(')')
      PsiElement(CLOSE_BACKQUOTE)('`')