∉ (not an element of)

Tests for set non-membership.

Syntax

• a ∉ A

  • a is any object

  • A is a set

Description

If a is any object and A a set, then a ∉ A returns true iff a is not an element of A.

If the cardinality of A is reasonably small, floating-point values are compared individually with epsilon. However, if the cardinality is very large, a different algorithm may be used to improve performance, which may not be epsilon-based.

The ∉ operator is implemented by the NotElementOf function.

Examples

A ≔ {−1, 0, 1}

{1, −1, 0}

sin(π) ∉ A

false

See also

• Set operators (list)