θ3⁡(4⁢z|4⁢τ)=B⁢θ3⁡(18⁢π-z|τ)⁢θ3⁡(18⁢π+z|τ)⁢θ3⁡(38⁢π-z|τ)⁢θ3⁡(38⁢π+z|τ),