\mathbb{Z} yields undefined control sequence error in latex article class
Load the amsfonts package,
\documentclass{article}
\usepackage{amsfonts}
% or you can use amssymb
%\usepackage{amssymb}
\begin{document}
$\mathbb{Z}$
\end{document}
Load the amsfonts package,
\documentclass{article}
\usepackage{amsfonts}
% or you can use amssymb
%\usepackage{amssymb}
\begin{document}
$\mathbb{Z}$
\end{document}