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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def parse(cls, parser, text, pos):
 """Imitates parsing a list grammar. Specifically, this grammar = [ SimpleValueUnit.date_specifiers_regex, SimpleValueUnit.arxiv_token_regex, SimpleValueUnit.token_regex, SimpleValueUnit.parenthesized_token_grammar ]. Parses plaintext which matches date specifiers or arxiv_identifier syntax, or is comprised of either 1) simple terminal (no parentheses) or 2) a parenthesized SimpleValue. For example, "e(+)" will be parsed in two steps, first, "e" token will be recognized and then "(+)", as a parenthesized SimpleValue. """

        found = False

        # Attempt to parse date specifier
        match = cls.date_specifiers_regex.match(text)
        if match:
            remaining_text, token, found = text[len(match.group(0)):], match.group(0), True
        else:
            # Attempt to parse arxiv identifier
            match = cls.arxiv_token_regex.match(text)
            if match:
                remaining_text, token, found = text[len(match.group()):], match.group(2), True
            else:
                # Attempt to parse a terminal token
                remaining_text, token = SimpleValueUnit.parse_terminal_token(parser, text)
                if type(token) != SyntaxError:
                    found = True
                else:
                    # Attempt to parse a terminal with parentheses
                    try:
                        # Enable parsing a parenthesized terminal so that we can accept {+, -, |} as terminals.
                        parser._parsing_parenthesized_terminal = True
                        remaining_text, token = parser.parse(text, cls.parenthesized_token_grammar, pos)

                        found = True
                    except SyntaxError:
                        pass
                    except GrammarValueError:
                        raise
                    except ValueError:
                        pass
                    finally:
                        parser._parsing_parenthesized_terminal = False

        if found:
            result = remaining_text, SimpleValueUnit(token)
        else:
            result = text, SyntaxError("expecting match on " + cls.__name__)

        return result