Assumptions:
TeX:
\sqrt{-z} = i \sqrt{z} z \in \left[0, \infty\right) \,\mathbin{\operatorname{or}}\, \left(z \in \mathbb{C} \,\mathbin{\operatorname{and}}\, \operatorname{Im}\!\left(z\right) \lt 0\right)
Definitions:
Fungrim symbol | Notation | Short description |
---|---|---|
Sqrt | Principal square root | |
ConstI | Imaginary unit | |
ClosedOpenInterval | Closed-open interval | |
Infinity | Positive infinity | |
CC | Complex numbers | |
Im | Imaginary part |
Source code for this entry:
Entry(ID("57af50"), Formula(Equal(Sqrt(Neg(z)), Mul(ConstI, Sqrt(z)))), Variables(z), Assumptions(Or(Element(z, ClosedOpenInterval(0, Infinity)), And(Element(z, CC), Less(Im(z), 0)))))