TeXipedia

lgroup

Represents a left group delimiter symbol, providing a vertically expandable bracket for grouping mathematical expressions.

Overview

Serves as a specialized mathematical delimiter that automatically adjusts its height based on the enclosed content, making it particularly useful for displaying large expressions or matrices.

  • Often paired with \rgroup to create matching delimiter pairs
  • Common in advanced mathematical typesetting where standard parentheses or braces are insufficient
  • Particularly useful in matrix notation and complex mathematical structures
  • Provides a more elegant alternative to standard brackets when vertical scaling is needed

Examples

Grouping terms in a matrix or array with large parentheses

⟮abcd⟯\left\lgroup\begin{matrix} a & b \\ c & d \end{matrix}\right\rgroup 
\left\lgroup\begin{matrix} a & b \\ c & d \end{matrix}\right\rgroup

Enclosing a multiline equation system with group delimiters

⟮x+y=12x−y=3⟯\left\lgroup\begin{array}{l} x + y = 1 \\ 2x - y = 3 \end{array}\right\rgroup 
\left\lgroup\begin{array}{l} x + y = 1 \\ 2x - y = 3 \end{array}\right\rgroup

Using group delimiters to enclose a set of mathematical expressions

f(x)=⟮x2x3x4⟯f(x) = \left\lgroup\begin{array}{c} x^2 \\ x^3 \\ x^4 \end{array}\right\rgroup 
f(x) = \left\lgroup\begin{array}{c} x^2 \\ x^3 \\ x^4 \end{array}\right\rgroup