\documentclass{article}


\usepackage{eufrak} % a \mathfrak parancshoz

\begin{document}

$A \setminus ( B \cup C ) = A \cap D$,\\
$\lnot(b\lor c) = \lnot b\land\lnot c$,\\
$x^3\pm y^3 = (x\pm y)(x^2\mp xy+y^2)$,\\
$\mathfrak A \oplus \mathfrak B$.

\end{document}