Assumptions:
TeX:
\sqrt{-z} = -i \sqrt{z}
z \in \left(-\infty, 0\right] \,\mathbin{\operatorname{or}}\, \left(z \in \mathbb{C} \,\mathbin{\operatorname{and}}\, \operatorname{Im}\!\left(z\right) \gt 0\right)Definitions:
| Fungrim symbol | Notation | Short description |
|---|---|---|
| Sqrt | Principal square root | |
| ConstI | Imaginary unit | |
| OpenClosedInterval | Open-closed interval | |
| Infinity | Positive infinity | |
| CC | Complex numbers | |
| Im | Imaginary part |
Source code for this entry:
Entry(ID("08bd37"),
Formula(Equal(Sqrt(Neg(z)), Mul(Neg(ConstI), Sqrt(z)))),
Variables(z),
Assumptions(Or(Element(z, OpenClosedInterval(Neg(Infinity), 0)), And(Element(z, CC), Greater(Im(z), 0)))))