def to_string(<EOL>self,<EOL>fmt: str = "<STR_LIT>",<EOL>canonicalize: bool = False,<EOL>decanonicalize: bool = False,<EOL>orthologize: str = None,<EOL>) -> str:
arg_string = "<STR_LIT:U+002CU+0020>".join([a.to_string(fmt=fmt) for a in self.args])<EOL>if fmt in ["<STR_LIT>", "<STR_LIT>"]:<EOL><INDENT>function_name = self.name_short<EOL><DEDENT>else:<EOL><INDENT>function_name = self.name<EOL><DEDENT>return "<STR_LIT>".format(function_name, arg_string)<EOL>
Convert AST object to string

        Args:
            fmt (str): short, medium, long formatted BEL statements
                short = short function and short relation format
                medium = short function and long relation format
                long = long function and long relation format

        Returns:
            str: string version of BEL AST