Assumptions:
TeX:
\theta_{3}\!\left(2 z , 4 \tau\right) = \frac{\theta_{3}\!\left(z , \tau\right) + \theta_{4}\!\left(z , \tau\right)}{2}
z \in \mathbb{C} \;\mathbin{\operatorname{and}}\; \tau \in \mathbb{H}Definitions:
| Fungrim symbol | Notation | Short description | 
|---|---|---|
| JacobiTheta | Jacobi theta function | |
| CC | Complex numbers | |
| HH | Upper complex half-plane | 
Source code for this entry:
Entry(ID("53fef4"),
    Formula(Equal(JacobiTheta(3, Mul(2, z), Mul(4, tau)), Div(Add(JacobiTheta(3, z, tau), JacobiTheta(4, z, tau)), 2))),
    Variables(z, tau),
    Assumptions(And(Element(z, CC), Element(tau, HH))))