Assuming

Assuming[assum, expr] evaluates expr with assum appended to $Assumptions, so that assum is included in the default assumptions used by functions such as Refine, Simplify, and Integrate.

Examples

Assuming[x > 0, Simplify[Sqrt[x^2]]]
(* x *)

Assuming[n ∈ Integers, Integrate[Sin[n x], {x, 0, 2 Pi}]]
(* 0 *)

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