represents the domain of real numbers, as in x∈Reals.
Reals
represents the domain of real numbers, as in x∈Reals.
Details
- x∈Reals evaluates immediately if x is a numeric quantity.
- Simplify [expr∈Reals,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 TemplateBox[{}, Reals]. This typeset form can be input using reals.
Examples
open all close allBasic 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 :
TraditionalForm formatting:
Related Guides
History
Introduced in 1999 (4.0) | Updated in 2017 (11.2)
Text
Wolfram Research (1999), Reals, Wolfram Language function, https://reference.wolfram.com/language/ref/Reals.html (updated 2017).
CMS
Wolfram Language. 1999. "Reals." Wolfram Language & System Documentation Center. Wolfram Research. Last Modified 2017. https://reference.wolfram.com/language/ref/Reals.html.
APA
Wolfram Language. (1999). Reals. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/Reals.html
BibTeX
@misc{reference.wolfram_2025_reals, author="Wolfram Research", title="{Reals}", year="2017", howpublished="\url{https://reference.wolfram.com/language/ref/Reals.html}", note=[Accessed: 16-November-2025]}
BibLaTeX
@online{reference.wolfram_2025_reals, organization={Wolfram Research}, title={Reals}, year={2017}, url={https://reference.wolfram.com/language/ref/Reals.html}, note=[Accessed: 16-November-2025]}