Algebras

$B(\H)$	the algebra of bounded linear operators on $\H$
$A$, $B$	$C^*$-algebras
$A^\mathrm{op}$	the opposite algebra of an algebra $A$
$\mathrm{1\!\!\!\:l}_{A}$	the identity in $A$
$M$, $N$	von Neumann algebras