\llbracket \rrbracketThe \llbracket \rrbracket command in LaTeX is used to create double square brackets, which are often used in mathematical expressions to denote intervals, commutators, or other specific mathematical constructs that require a distinct type of bracket.
Denotes an interval or a set including elements between a and b.
\llbracket a, b \rrbracketRepresents the commutator of two operators A and B in quantum mechanics.
\llbracket A, B \rrbracket = AB - BAUsed to denote a special function or operation applied to x, depending on context.
\llbracket x \rrbracket