Latex compile my code and it's kinda ok, but I don't understand an error it gives me
This is part of my code that doesn't work
\documentclass[paper=a4, fontsize=12pt]{scrartcl}
\usepackage[T1]{fontenc}
\usepackage{fourier}
\usepackage[english]{babel}
\usepackage{amsmath,amsfonts,amsthm}
\usepackage{enumerate}
\begin{document}
\section*{Exercise 1}
\textit{Let $(\Omega, \varepslion, \mathbb{P})$
be a probability space, and take $\mathcal{F}(\cdot)$
to be a filtration of $\sigma$-algebras.
Assume X be an integrable random variable, and define
$X(t):=\mathbb{E}(X|\mathcal{F}(t))$ for times $t \geqslant 0$.
Show that $X(\cdot)$ is a martingale.
}
\end{document}
Latex (I'm using latexian on mac) give me an error in the last line (the parenthesis } )telling "undefined control sequence". I really can't understand why it doesn't work. If I erase the }, it doesn't give me any error (but the preview tell me "error view console")
I used this code other times (same thing, different worlds in \textit{}) and always worked fine.
\documentclass{...}
and ending with\end{document}
.\varepslion
where two letter are exchanged.