\documentclass{article}

\documentclass{article}
\usepackage{amsmath} % pkg required by EasyLatex
\usepackage{amsfonts} % pkg required by EasyLatex
\usepackage{amssymb} % pkg required by EasyLatex
\usepackage{psfrag} % pkg required by EasyLatex
\usepackage[dvips]{graphicx} % pkg required by EasyLatex

\begin{document}

Test of finding single line naked eqn which has an escaped = sign (i.e. should NOT be found)

$B_{new}$ = $B - X_{IN}$ + $X_{OUT}$

\end{document}