User blog comment:Scorcher007/Analysis DAN up to Z2/@comment-11227630-20180828111803/@comment-31580368-20180828112926

Sorry for not following the syntax, I just got used to working in the style of Berd's massive notation. S[a+1] - just simplified notation for a+1-stable ordinal. S[Ωa+1] - just simplified notation for (+)-stable ordinal, e.t.c. S2[...] means 2-stable ordinal.