答案1
答案2
\usepackage[T1]{fontenc}
使用or有两种可能性\usepackage{amssymb}
:
\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage{amssymb}
\begin{document}
\centering
$\theta_{nc}^D < \theta^D$\\
$\theta_{nc}^D > \theta^D$\\
$\theta_{nc}^D = \theta^D$\\
$\theta_{nc}^D \leq \theta^D$\\
$\theta_{nc}^D \geq \theta^D$\\
$\theta_{nc}^D\lesseqqgtr \theta^D$
\end{document}