This is documentation for Mathematica 8, which was
based on an earlier version of the Wolfram Language.
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is an option for functions such as Simplify, Refine, and Integrate that specifies default assumptions to be made about symbolic quantities.
  • The assumptions can be equations, inequalities, or domain specifications, or lists or logical combinations of these.
  • xReals 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.
$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:
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