On 15 May 2016, at 19:32, Hans Åberg
wrote: On 15 May 2016, at 19:14, Hans Hagen
wrote: On 5/15/2016 2:33 PM, Hans Åberg wrote:
Maybe a way to distinguish between unary prefix operator “-“, and binary infix operator “-“: {} is interpreted as an empty operand, thus infix “-", whereas \relax is removed from the input meaning no operand, so prefix “-“. But \relax can have sub-/super-scripts, just as {}, and then in both cases, “–“ becomes binary:
\startformula {}^2 - a \stopformula \startformula \relax^2 - a \stopformula
why not use something more natural unicode
\startformula \zwnj^2 - a \stopformula
The TeX Book recommends using {} for superscripts to the lefts side, eg. \startformula {}_a^b C_d^e \stopformula
In addition to this usage, one can use {} for tensor-component notation: \setupbodyfont[xits,10pt] \setupmathematics[integral=nolimits] The Ricci tensor \startformula\relax R^i{}_{ikj} \stopformula There might be module or page for tensor component notation, if somebody would request it: There is a standard ISO 80000-2 [1-2] for natural sciences and technology, but not for pure math then, which I recall call for tensors expanded into components to be typed in sans-serif. In pure math, one is using serifs as always, with some other differences, usually sticking to a mathematically complete description with summation signs and basis. 1. http://www.ise.ncsu.edu/jwilson/files/mathsigns.pdf 2. https://en.wikipedia.org/wiki/ISO_80000-2