# Reals

represents the domain of real numbers, as in xReals.

# Details • xReals evaluates immediately if x is a numeric quantity.
• Simplify[exprReals,assum] can be used to try to determine whether an expression corresponds to a real number under the given assumptions.
• (x1|x2|)Reals and {x1,x2,}Reals test whether all xi are real numbers.
• Within Simplify and similar functions, objects that satisfy inequalities are always assumed to be real.
• Reals is output in StandardForm or TraditionalForm as . This typeset form can be input using reals .

# Examples

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## Basic Examples(3) is a real number:

If is a real number, so is :

Find real solutions of an equation:

## Scope(5)

Test domain membership of a numeric expression:

Make domain membership assumptions:

Specify the default domain over which a function should work:

Test whether several numbers are real numbers:

If any number is explicitly non-real, the result is False:

## Properties & Relations(3)

Reals contains Rationals, Integers, and Primes:

Reals is contained in Complexes:

Reals neither contains nor is contained in Algebraics:

Introduced in 1999
(4.0)
|
Updated in 2017
(11.2)