User blog comment:Chronolegends/Ordinal Notations 0 : Up to the Gamma Fixed Point/@comment-28606698-20170118181337

For Single argument Veblen function:

if $$\alpha$$ is a limit ordinal and $$\lambda=\beta+1$$ then $$\varphi_{\alpha}(\beta+1) [n] = \varphi_{\alpha [n]}(\varphi_{\alpha}(\beta)+1) $$

not $$ \varphi_{\alpha [n]}(\varphi_{\alpha}(\beta)) $$