User blog comment:Alemagno12/Analysis of Edwin Shade's ''three-symbol'' notation for ordinals/@comment-80.98.179.160-20171107130723

[(][(][)]|[(][)][)] is ω opening parens then ω pairs of parens then | then ω pairs of parens then ω closing parens. That implies at least ωω. Then we delete emptiable parens (without removing others).