# [texhax] \Pr and displaylimits

Sun Aug 19 05:12:46 CEST 2007

Hi,

I have a question about the rationale of defining \Pr with
displaylimits.

In plain.tex \Pr is defined without \nolimits as

\def\Pr{\mathop{\rm Pr}}

Other macro packages (LaTeX and ConTeXt) provide hooks for changing
operator fonts, but basically copy this definition without the
nolimits. In the books that I have seen, limits on Pr have the visual
effect of

\Pr\nolimits^{g}(X \mid Y)

So why did Knuth choose not to have a \nolimit with \Pr.
Are there branches of mathematics where limits with Pr should be
displaylimits?