What causes "Not support lim {e}" in PaddlePaddle/PaddleOCR?

Extend LIM_FUNC in paddleocr/_doc2md/math/latex_dict.py with the missing operator, e.g. add "inf": "\\inf_{{{lim}}}" and "sup": "\\sup_{{{lim}}}".

PaddlePaddle/PaddleOCR · error · RuntimeError

Not support lim {e}

Error message

Not support lim {e}

What it means

Raised by the OMML (Office Math Markup Language) to LaTeX converter when a lower-limit construct (m:limLow) whose base expression is not one of the recognized functions. LIM_FUNC in paddleocr/_doc2md/math/latex_dict.py only maps "lim", "max", and "min", so any other base (e.g. "sup", "inf", "gcd" or a non-text run) cannot be converted and the converter aborts with RuntimeError. It occurs during doc-to-markdown conversion of Word documents containing equations.

Source

Thrown at paddleocr/_doc2md/math/omml.py:358

        if len(rows) == 1:
            row = rows[0]
            tag_match = re.search(r"\\#\s*\(([^)]*)\)\s*$", row)
            if tag_match:
                formula = row[: tag_match.start()].rstrip()
                tag_content = tag_match.group(1)
                return f"{formula}\\tag{{{tag_content}}}"
            return row

        return ARR.format(text=BRK.join(rows))

    def do_limlow(self, elm):
        """
        the Lower-Limit object
        """
        t_dict = self.process_children_dict(elm, include=("e", "lim"))
        latex_s = LIM_FUNC.get(t_dict["e"])
        if not latex_s:
            raise RuntimeError("Not support lim {}".format(t_dict["e"]))
        else:
            return latex_s.format(lim=t_dict.get("lim"))

    def do_limupp(self, elm):
        """
        the Upper-Limit object
        """
        t_dict = self.process_children_dict(elm, include=("e", "lim"))
        return LIM_UPP.format(lim=t_dict.get("lim"), text=t_dict.get("e"))

    def do_lim(self, elm):
        """
        the lower limit of the limLow object and the upper limit of the limUpp function
        """
        return self.process_children(elm).replace(LIM_TO[0], LIM_TO[1])

    def do_m(self, elm):
        """

View on GitHub (pinned to 2661c7c0ef)

Solutions

Extend LIM_FUNC in paddleocr/_doc2md/math/latex_dict.py with the missing operator, e.g. add "inf": "\\inf_{{{lim}}}" and "sup": "\\sup_{{{lim}}}".
Wrap the doc2md math conversion call in try/except and skip/keep the original XML for the failing formula so the rest of the document still converts.
Edit the equation in the source document to use a form the converter supports (plain \lim) and re-convert.

Example fix

# paddleocr/_doc2md/math/latex_dict.py
# before
LIM_FUNC = {
    "lim": "\\lim_{{{lim}}}",
    "max": "\\max_{{{lim}}}",
    "min": "\\min_{{{lim}}}",
}
# after
LIM_FUNC = {
    "lim": "\\lim_{{{lim}}}",
    "max": "\\max_{{{lim}}}",
    "min": "\\min_{{{lim}}}",
    "inf": "\\inf_{{{lim}}}",
    "sup": "\\sup_{{{lim}}}",
    "gcd": "\\gcd_{{{lim}}}",
}

Defensive patterns

Strategy: try-catch

Validate before calling

from paddleocr._doc2md.math.latex_dict import LIM_FUNC

def limlow_convertible(base_text: str) -> bool:
    return base_text in LIM_FUNC

Try / catch

try:
    md = converter.convert(docx_path)
except RuntimeError as e:
    if "Not support lim" in str(e):
        logger.warning("Skipping unsupported limLow formula: %s", e)
        md = convert_without_math(docx_path)  # fallback mode
    else:
        raise

Prevention

Audit Word docs for \inf/\sup/\gcd-style limit constructs before batch conversion
Extend LIM_FUNC once per newly encountered operator instead of skipping
Log the offending t_dict['e'] value from the chained exception to identify the operator to add

When it happens

Trigger: Converting a .docx with PaddleOCR's doc2md pipeline where an equation contains an m:limLow element whose m:e resolves to text not in {"lim", "max", "min"} (for example \inf, \sup, \oint limits, or a nested construct instead of a plain run).

Common situations: Scientific/academic Word documents with \inf_{n} or \sup_{x} expressions; documents produced by different equation editors that emit limLow for unusual operators; conversion failing mid-document on one specific formula.

Related errors

AI-assisted analysis of PaddlePaddle/PaddleOCR@2661c7c0ef (2026-08-14). Data as JSON: /api/errors/71a747348352e7ef. Report an issue: GitHub.