[r-t] Re: proofs

[Robin Woolley]

Further to Richard (Smith)'s comments, I confirm that, when I originally did
the analysis, I used X to represent inv(C).A which means 'the inverse of C
transposing A'. Since inv(X) also appears in the analysis, inv(A).C would
also be usable. As he says, the other way round would not work.

The first result (symmetric sections) is useful as it justifies halving the
work in falseness extraction,

The second result (inverted sections) is really only of practical use when
the inversion appears in the last section, cf. Pudsey & Lincoln,

The third result is merely interesting.

I didn't expect this simple idea to take on so much a life of its own. The
nice thing is that it can be done from simple algebra at lower than A level
standard. I don't think I'll offer my proof of the incidence of the inverse
of a false course being the original incidence reversed.

b.t.w., is there an isomorphism between the falseness of K626 and K522 (for
example) - the first is regular and the second is irregular just differing
at the half-lead?

Regards
Robin.