On 2012-07-11, Hans Aberg <haber...@telia.com> wrote: > There are a number of other incompatibilities between original TeX and > Unicode: > > For example, ASCII letters are in TeX math mode typeset in italics, but > Unicode has a mathematical italics style, so ASCII letters should be typeset > upright in a strict Unicode mode. And similar for Greek letters, I gather.
Unicode is about plain text. TeX is about fine typesetting. There's no reason why TeX should typeset ASCII as upright, any more than it should typeset "\begin{section}" as that literal string! The use of ASCII characters in math mode is simply an input convention, to indicate the desired output of italic letters in a style appropriate for single-letter mathematical variables. The use of other Unicode characters in TeX input files is also simply an input convention; how they get typeset depends on many other things than what they look like in the code charts. -- The University of Edinburgh is a charitable body, registered in Scotland, with registration number SC005336.