Comment on ODF 1.2 OpenFormula (6.5.2 MDETERM)

[Andrea Pescetti <pescetti@openoffice.org>]

In the version of OpenFormula currently under public review as per
http://lists.oasis-open.org/archives/tc-announce/201007/msg00004.html
the definition of 6.5.2 MDETERM contains the following text:
  ---
where P denotes a permutation of the numbers 1, 2, ..., n and sgn(P)
is the sign of the permutation, which is +1 for an even amount of
permutations and -1 for an odd amount.
  ---
This is wrong, as it mixes permutations and permutation inversions.
See http://mathworld.wolfram.com/PermutationInversion.html

A way to fix it with minimal impact is the following:
  ---
where P denotes a permutation of the numbers 1, 2, ..., n and sgn(P)
is the sign of the permutation, which is +1 for even permutations
(i.e., permutations where it is necessary to apply an even number of
switches of adjacent numbers to restore the original sequence), -1
otherwise.
  ---

Regards,
  Andrea Pescetti - Italian N-L Project Lead, OpenOffice.org