Talk: Yoichi Nagumo

The nested square roots aren't a limit $\lim$.
A limit is only used if there is a variable approaching something.
Like $\lim _{x\searrow 0}{\frac {1}{x}}=\infty$ is an example of a limit.

Also the symbol is $\phi$ which was the usual placeholder for the golden ratio in it's characteristic equation.
$\phi^2=\phi+1$
Nowadays $\varphi$ is preferred.