A delimiter symbol representing a backward-slanting line commonly used in set notation and logical expressions.
Examples
Set difference notation
A \backslash B \text{ represents elements in A that are not in B}
Left coset notation in group theory
G \backslash H \text{ denotes left cosets of H in G}
Quotient space in topology
X \backslash \sim \text{ denotes the quotient space of X by relation } \sim