I am trying to write an generalised limit operator, which look approximately like the standard \lim, except it has an additional symbol in front, connected by a hyphen (see example below). I would very much like this generalised limit to really look like the good old \lim; in particular, if I take limit over a variable x, then I would like the symbol x to be placed below. I almost managed to accomplish this by exploiting the old \lim, and adding the prefix:

> p \!\! - \!\! \lim_x 

However, if I replace x by a longer string (say, several variables), I get too much whitespace. I tried grouping the limit into a single object, like below, but this leads to the variable being placed right of the limit symbol, not below:

> {p \!\! - \!\! \lim}_x 

Could someone please advise me what is the best way of writing such a limit?

Here is a minimal example and the output.


Naive example: 
p-\lim_{x} f(x), \qquad
p-\lim_{x_1,x_2,\dots,x_n} f(x_1,x_2,\dots,x_n)

With \verb"\!" used for indentation, without grouping: 
p\!\!-\!\!\lim_{x} f(x), \qquad
p\!\!-\!\!\lim_{x_1,x_2,\dots,x_n} f(x_1,x_2,\dots,x_n)

With \verb"\!" used for indentation, plus grouping  : 
{p\!\!-\!\!\lim}_{x} f(x), \qquad
\operatorname{p\!\!-\!\!\lim}\limits_{x_1,x_2,\dots,x_n} f(x_1,x_2,\dots,x_n)


enter image description here


You can use


in your preamble, which will define a command \plim which you can use in your document with, for example,

\plim_{x\to\infty} f(x)

This will produce a roman (upright) 'p'. If you want an italic 'p', the definition should be

| improve this answer | |
  • The ā€œpā€ will be upright, which probably isn't wanted. – egreg Jul 28 '13 at 11:17
  • This is precisely what I needed, thank you! I replaced \DeclareMathOperator* by a \newcommand with \operatorname* so that I could replace p by other, but other than that, you solution works perfectly. – Jakub Konieczny Jul 28 '13 at 12:11
  • The right command is \mathnormal, but this is already covered in the question I linked as duplicate. – egreg Jul 28 '13 at 12:37

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