diff --git a/README.md b/README.md
index bcc9428..e719cc0 100644
--- a/README.md
+++ b/README.md
@@ -258,12 +258,14 @@ pdf2zh example.pdf -t 1
 
 <h2 id="todo">TODO</h2>
 
-- [ ] Parse layout with [PaddleX (17 cls)](https://github.com/PaddlePaddle/PaddleX/blob/17cc27ac3842e7880ca4aad92358d3ef8555429a/paddlex/repo_apis/PaddleDetection_api/object_det/official_categories.py#L81), [PaperMage (27 cls)](https://github.com/allenai/papermage/blob/9cd4bb48cbedab45d0f7a455711438f1632abebe/README.md?plain=1#L102), [SAM2](https://github.com/facebookresearch/sam2)
+- [ ] Parse layout with [PaddleX](https://github.com/PaddlePaddle/PaddleX/blob/17cc27ac3842e7880ca4aad92358d3ef8555429a/paddlex/repo_apis/PaddleDetection_api/object_det/official_categories.py#L81), [PaperMage](https://github.com/allenai/papermage/blob/9cd4bb48cbedab45d0f7a455711438f1632abebe/README.md?plain=1#L102), [SAM2](https://github.com/facebookresearch/sam2)
 
 - [ ] Fix page rotation, table of contents, format of list
 
 - [ ] Fix pixel formula in old paper
 
+- [ ] Support multiple language with [Noto Font](https://fonts.google.com/noto), [Ubuntu Font](https://design.ubuntu.com/font)
+
 <h2 id="acknowledgement">Acknowledgements</h2>
 
 - Document merging: [PyMuPDF](https://github.com/pymupdf/PyMuPDF)
diff --git a/pdf2zh/converter.py b/pdf2zh/converter.py
index 69fd9d7..c5a5a83 100644
--- a/pdf2zh/converter.py
+++ b/pdf2zh/converter.py
@@ -528,10 +528,10 @@ def vflag(font, char):  # 匹配公式（和角标）字体
                         pstk[-1][5] = child.font
                     sstk[-1] += child.get_text()
                 else:                                                       # 公式入栈
-                    if (                                                    # 根据公式右侧的文字修正公式的纵向偏移
+                    if (                                                    # 根据公式左侧的文字修正公式的纵向偏移
                         not vstk                                            # 1. 当前字符是公式的第一个字符
                         and cls == xt_cls                                   # 2. 当前字符与前一个字符属于同一段落
-                        and child.x0 > xt.x0                                # 3. 当前字符在前一个字符右侧
+                        and child.x0 > xt.x0                                # 3. 前一个字符在公式左侧
                     ):
                         vfix = child.y0 - xt.y0
                     vstk.append(child)