我怎样才能制作直角符号⦝？

Question

如何使用 LaTeX 制作符号 ⦝ （以点为单位的直角，U+299D）？

（我尝试了 Detexify 和综合 LATEX 符号列表）

Answer 1

TikZ 版本：

\documentclass{article}
\usepackage{amsmath}
\usepackage{tikz}

\newcommand\RADot{%
  \mathord{%
    \mspace{1mu}%
    \text{\radot}%
    \mspace{1mu}%
  }%
}

\newcommand\radot{%
    \tikz[line cap=round,x=1ex,y=1ex,line width=0.3pt]
    {\draw (0,1) |- (1,0) (0.55,0) arc(0:90:0.55); \fill (0.23,0.23) circle (0.05);}%
}

\begin{document}

$a\RADot_{\RADot_{\RADot}}$

\end{document}

Answer 2

图片模式！

\documentclass{article}
\usepackage{amsmath,pict2e}

\newcommand{\measuredrightanglewithdot}{%
  \mathord{%
    \mspace{1mu}%
    \text{\mrawd}%
    \mspace{1mu}%
  }%
}

\newcommand{\mrawd}{%
  \setlength{\unitlength}{1ex}%
  \begin{picture}(1,1)
  \roundcap
  \polyline(0,1)(0,0)(1,0)
  \put(0,0){\arc[0,90]{0.5}}
  \put(0.2,0.2){\circle*{0.1}}
  \end{picture}%
}

\begin{document}

$a\measuredrightanglewithdot_{\measuredrightanglewithdot}$

\end{document}

或者，也可以从 STIX 字体导入它。

\documentclass{article}
\usepackage{amsmath,pict2e}

% import from STIX
\DeclareFontEncoding{LS1}{}{}
\DeclareFontSubstitution{LS1}{stix}{m}{n}
\DeclareFontFamily{LS1}{stixfrak}{\skewchar\font127 }
\DeclareFontShape{LS1}{stixfrak}{m}{n} {<-> stix-mathfrak}{}
\newcommand{\rightanglemdot}{\text{\usefont{LS1}{stixfrak}{m}{n}\symbol{"3C}}}
%%%

% picture mode
\newcommand{\measuredrightanglewithdot}{\mathord{\mspace{1mu}\text{\mrawd}\mspace{1mu}}}
\newcommand{\mrawd}{%
  \setlength{\unitlength}{1ex}%
  \begin{picture}(1,1)
  \roundcap
  \polyline(0,1)(0,0)(1,0)
  \put(0,0){\arc[0,90]{0.5}}
  \put(0.2,0.2){\circle*{0.1}}
  \end{picture}%
}

\begin{document}

$a\measuredrightanglewithdot_{\measuredrightanglewithdot}$ (picture mode)

$a\rightanglemdot_{\rightanglemdot}$ (STIX)

\end{document}