TeXipedia

lBrace

Renders a large left curly brace that automatically scales to match the height of its content.

Overview

Essential for mathematical notation where content needs to be grouped or organized with scalable delimiters. Particularly valuable in:

  • Set-builder notation and set definitions
  • Piecewise functions and equations
  • Matrix and array constructions requiring grouped elements
  • Mathematical statements where multiple lines or expressions need to be unified under a single brace

Typically paired with \rBrace for complete enclosure, offering better scaling and appearance compared to standard keyboard braces.

Examples

Defining a piecewise function with a left brace.

f(x)=⦃x2if x≥0−x2if x<0f(x) = \lBrace\begin{array}{ll} x^2 & \text{if } x \geq 0 \\ -x^2 & \text{if } x < 0 \end{array} 
f(x) = \lBrace\begin{array}{ll} x^2 & \text{if } x \geq 0 \\ -x^2 & \text{if } x < 0 \end{array}

System of equations with left brace notation.

⦃2x+y=5x−y=1\lBrace\begin{array}{l} 2x + y = 5 \\ x - y = 1 \end{array} 
\lBrace\begin{array}{l} 2x + y = 5 \\ x - y = 1 \end{array}

Set builder notation with explicit left brace.

S=⦃x∈R:x>0 and x<1⦄S = \lBrace x \in \mathbb{R} : x > 0 \text{ and } x < 1 \rBrace 
S = \lBrace x \in \mathbb{R} : x > 0 \text{ and } x < 1 \rBrace