上面的 latex 中的括号问题

Question

您在 delta 符号中看到的部分中的括号符号太长了。我无法将其作为固定括号来使用。我们使用了，\bigl但它不起作用。我们使用了\underbrace，但无法得到结果。唯一的问题是我想在表达式 (< delta) 下的方括号中放置一个完整的括号。

\begin{tikzpicture}
\draw[step=1cm,gray,very thin] (-2,-3) grid (5,5);
\draw[thick] (-3,-4) -- (-3,5.5);
\draw[thick] (-6,1) -- (6.5,1);
\draw (-4,5) node[font = {\Huge}, black]{$M$};
\draw (-4,-2) node[font = {\Huge}, black]{$M$};
\draw (-2,1) node[below left, font = {\Huge}, black]{$a$};
\draw (5,1) node[below right, font = {\Huge}, black]{$b$};
\draw (5,5) node[below right, font = {\Huge}, black]{$\bigl\{\lt\Tilde{\epsilon}$};
\draw (-2,6) node[below right, font = {\Huge}, black]{$\lt \delta$};
\end{tikzpicture}

Answer 1

我可能会使用decorations库并使用 Ti 绘制括号钾Z：

\documentclass[border=10pt]{standalone}
\usepackage{tikz}
\usetikzlibrary{decorations.pathreplacing, calligraphy}

\begin{document}
\begin{tikzpicture}[thick, font={\Huge}]
    \draw[step=1cm, gray, very thin] (-2,-3) grid (5,5);
    \draw (-3,-4) -- (-3,5.5);
    \draw (-6,1) -- (6.5,1);
    \node at (-4,5) {$M$};
    \node at (-4,-2) {$M$};
    \node[below left] at (-2,1) {$a$};
    \node[below right] at (5,1) {$b$};
    \draw[decorate, decoration={calligraphic brace}] ([xshift=5pt]5,5) -- ([xshift=5pt]5,4)
        node[midway, right=5pt, anchor=west]{$< \tilde{\epsilon}$};
    \draw[decorate, decoration={calligraphic brace}] ([yshift=5pt]-2,5) -- ([yshift=5pt]0,5)
        node[midway, above=5pt, anchor=south]{$< \delta$};
\end{tikzpicture}
\end{document}