# Re: OASIS: Infix Operator "^"

*From*: Leonard Mada <discoleo gmx net>
*To*: gnumeric-list gnome org, office-comment lists oasis-open org
*Subject*: Re: OASIS: Infix Operator "^"
*Date*: Fri, 23 Feb 2007 19:41:03 +0200

Andreas J. Guelzow wrote:

`NO, there is NO such unary operator: -x^2 = -x * -x = + x^2, THIS is
``NONSENSE. Such a unary operator does NOT exist.
``
`

What is the - in -x if not a unary operator?

`
`

`Well, the true unary operator has the fantastic property that -x^2 !=
``+x^2, while that described in the OASIS document has the strange
``property that -x^2 = +x^2.
`

`This is basic math I learned back in school while I was in the 5th
``grade. It did NOT change over time.
`
Though, there is even more to this. I try to be constructive:

In any case, OpenFormula describes the syntax used in a file.

`That is a poor format then, and surely NON-portable IF I would like to
``import the file in a serious statistical program. And what will the
``future being, maybe someday even spreadsheets will be required to abide
``to mathematical rules breaking everything.
`
1. CASE 2^3^4

`This is simple. The average Joe won't use 2^3^4. It is more the
``mathematically advanced, who will know what the precedence is.
``Therefore, I believe this won't be a pain to interpret correctly. FOR
``older files (ODF 1.x? & Excel) interpret like it was used to be. For
``newer one, there should be NO problem to interpret it differently.
`
*Now, why saving 2^3^4 this way in the spreadsheet?*

`I remember that some years back, the decision was taken to store only 2
``digit years. And then came y2k. Is it that difficult to automatically
``store 2^3^4 either as 2^(3^4) (the correct version), or as (2^3)^4
``(incorrect version), so that EVERY software will ALWAYS interpret it
``correctly/non-ambiguously?
`

`I strongly recommend, that the OASIS document clearly specifies, that
``*Cases that could be mathematically ambiguous should be automatically
``RESOLVED using appropriately placed brackets* (whatever this resolution
``would be), so NO program, user, or changes over time will affect the
``results/interpretation.
`
2. CASE -4^2

`This is more difficult to change, because average Joe might believe the
``current handling of this is correct. BUT see the first case:
``transforming this into (-4)^2 would remove confusion and allow for
``consistency of the formula in different programs and in the future.
`
CONCLUSION
============

`If you wish to develop a solid format, strongly consider implementing a
``mathematically NON-ambiguous storing and displaying method. Otherwise,
``other programs (like the advanced statistical and mathematical programs)
``will yield ERRORS, making the use of these spreadsheets inappropriate in
``fields where serious data analysis is undertaken.
`
Leo

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