I have a minor error in the below code, although it gets compiled without error, but it complains with:
Error: undefined control sequence
I want to get
child(V)={ u ∈ N(v) | d(root,u)=d(root,v)+1 }
as output
Here is the code:
\documentclass[runningheads,a4paper]{llncs}
\usepackage{amssymb}
\setcounter{tocdepth}{2}
\usepackage{graphicx}
\usepackage[latin1]{inputenc}
\usepackage[english]{babel}
\usepackage{url}
\usepackage{float}
\usepackage{booktabs}
\usepackage{multirow}% http://ctan.org/pkg/multirow
\usepackage{hhline}% http://ctan.org/pkg/hhline
\usepackage{mathtools}
\usepackage{amsmath}
\usepackage[english]{babel}
\usepackage{booktabs,array}
\setcounter{secnumdepth}{5}
\begin{document}
$$\child(V)=\{ u \in N(v) | d(root,u)=d(root,v)+1 \}$$
\end{document}
Best Answer
You should declare
\child
as a math operator, but also use\mathrm
forroot
Never use math italic for words, it separates the letters to make it look like a product of variables. Also use\[
never$$
in LaTeX.