TeXipedia

mid

Denotes a conditional separator in set-builder notation, creating a clear division between a set's elements and their defining conditions.

Overview

Essential for writing mathematical sets in a formal and precise manner, particularly in set theory, logic, and abstract mathematics.

  • Commonly used in set-builder notation to separate the set variable from its constraints
  • Appears frequently in discrete mathematics and formal proofs
  • Helps express complex set definitions clearly by distinguishing between the set elements and their properties
  • Often encountered in advanced algebra, topology, and theoretical computer science when defining specific subsets or custom sets

Examples

Define a set using set-builder notation with a condition.

{xRx>0}\{x \in \mathbb{R} \mid x > 0\}
\{x \in \mathbb{R} \mid x > 0\}

Specify a conditional probability.

P(AB)=P(AB)P(B)P(A \mid B) = \frac{P(A \cap B)}{P(B)}
P(A \mid B) = \frac{P(A \cap B)}{P(B)}

Define a function's domain with multiple conditions.

{xRx<1 or x>1}\{x \in \mathbb{R} \mid x < -1 \text{ or } x > 1\}
\{x \in \mathbb{R} \mid x < -1 \text{ or } x > 1\}