and got from pdflatex a fancy calligraphic math X, which was sufficiently fancy to be visibly distinct from the remaining italicized X in X_1 till X_n:
However, in the more modern times, mathptmx has been obsoleted in favor of newtx.
to pdflatex results in a dull
The distinction between the first X and the remaining occurrences is far less prominent. This is unfortunate, as it requires additional attention from the reader to distinguish between the two.
For pdflatex, what is the advised way of getting the fancy math X, such as in mathptmx, , or similar, if you use newtxtext and newtxmath for standard text and math fonts? Yes, I know there is mathrsfs, which is not obsolete in CTAN but is pretty dated (1999-06-30 is the date of the file http://mirrors.ctan.org/macros/latex/contrib/jknappen/mathrsfs.sty on the CTAN file system and 1996-01-01 is the internal date stated inside http://mirrors.ctan.org/macros/latex/contrib/jknappen/mathrsfs.sty). Is it still advisable to use mathrsfs+
\mathscror are there better options?