Subject: Re: OASIS: Infix Operator "^"
Andreas J Guelzow wrote: > Unfortunately there is a > significant discrepancy of the normal mathematical definitions and what > is used in spreadsheets. > However, there is NO discrepancy what mathematicians use. Also, dedicated mathematical programs are fairly consistent with these precedence rules. I therefore recommend to every developer of a mathematical standard to have first a look at Mathematica. > [Of course there is an issue here: in OOo ^ appears to be > left-associative while in Gnumeric it is right-associative.] > >> 1. “^” is left-associative, not right-associative!!! >> > > Wherever I look I find that ^ is indeed right-associative contrary to > your claim. ... I meant right-associative! [The former was actually the definition inside the OASIS document.] So, 2^3^4 = 2^(3^4) as I indicated in my previous post, too. [the formulas were correct] >> 2. The classic ERROR: -4^2 >> Mathematically, this yields always -(4^2)=-16, NEVER +16!!! >> There is NO unary operator in mathematics that converts a number to its >> negative, like described in the documents. >> > > This is utter nonsense. Of course there is such a unary operator. ... NO, there is NO such unary operator: -x^2 = -x * -x = + x^2, THIS is NONSENSE. Such a unary operator does NOT exist. We can invent a new algebra with such an operator. It would simplify some things, we would never have to use -x^2, because it would evaluate to +x^2 anyway. But it would be utter nonsense. Kind regards, Leonard Mada