Assumptions
Details

- The typical default setting is Assumptions:>$Assumptions.
- The assumptions can be equations, inequalities, or domain specifications, or lists or logical combinations of these.
- Assuming modifies $Assumptions and so modifies the value of default settings for Assumptions options.
- x∈Reals can be used to specify that x should be treated as a real variable.
- Quantities that appear algebraically in inequalities are always assumed to be real.
Examples
open all close allBasic Examples (1)
Properties & Relations (3)
$Assumptions is the default value of Assumptions for most functions that have the option:
Assuming locally sets the value of $Assumptions:
Block can also be used to locally set the value of $Assumptions:
Here the assumptions from Assuming are not used inside Block:
Assumptions from nested Assuming are combined:
Tech Notes
History
Introduced in 1996 (3.0) | Updated in 2003 (5.0)
Text
Wolfram Research (1996), Assumptions, Wolfram Language function, https://reference.wolfram.com/language/ref/Assumptions.html (updated 2003).
CMS
Wolfram Language. 1996. "Assumptions." Wolfram Language & System Documentation Center. Wolfram Research. Last Modified 2003. https://reference.wolfram.com/language/ref/Assumptions.html.
APA
Wolfram Language. (1996). Assumptions. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/Assumptions.html
BibTeX
@misc{reference.wolfram_2025_assumptions, author="Wolfram Research", title="{Assumptions}", year="2003", howpublished="\url{https://reference.wolfram.com/language/ref/Assumptions.html}", note=[Accessed: 04-August-2025]}
BibLaTeX
@online{reference.wolfram_2025_assumptions, organization={Wolfram Research}, title={Assumptions}, year={2003}, url={https://reference.wolfram.com/language/ref/Assumptions.html}, note=[Accessed: 04-August-2025]}