User:Ivan

Some notes on style

• There are legacy images (e.g., m06542010.png) in this wiki with a lower ellipsis where one might expect a midline ellipsis instead. I used to write \ldots in order to preserve style, however, the printed Encyclopaedia of Mathematics does use midline ellipses and there are also legacy images where the multiplication dot is corrupted to a lower dot. To do:
  • Replacing \ldots where appropriate.
  • Proper spacing with differentials, consistent use of \quad and \qquad.
• According to ISO 80000-2:2009, explicitly defined, context-independent functions, mathematical constants and well-defined operators are printed in roman (e.g., $\mathrm C^k_n$, $\mathrm dx$, $\mathrm e$^{$\mathrm i$π}). Note, however, that physical constants are written in italics, e.g., $m_\mathrm e$ for the electron mass and $e$ for the elementary charge. It may be argued that $\mathrm P$ clearly stands for probability; on the other hand, there are different probability measures and $P$ may be used as a variable for such a measure (just as $p$ is often used as a variable for a prime number). (ISO 3534-1:2006 uses italic $P$, so I will stick to that.)
• The standard document is pretty sloppily written. In the remark to item 2-13.2, a minus appears that looks rather like a hyphen. The spacing is inconsistent and $\mathrm{Ei}x$ as well as $\mathrm{li}x$ are found even though, according to the standard, there should be a thin space in such cases. $\bar x_a$ for the arithmetic mean (the subscript may be omitted) appears with an italic $a$ which barely makes any sense. (In the remarks row, there is talk about subscript h for the harmonic, subscript g for the geometric and subscript q or rms for the quadratic mean or root mean square; “h”, “g”, “q” and “rms” appear upright there, although the corresponding notations are not actually displayed.)