The default limit operator displays “lim” with a small l. I wish to redefine it to display “Lim” that is, with a capital L like shown below.

enter image description here

  • Welcome to TeX.SE! Which documentclass do you use, which math-packages? Please show us a short compilable TeX code resulting in your issue!
    – Mensch
    Sep 26 at 20:14
  • 4
    \usepackage{mathtools} \DeclareMathOperator*{\Lim}{Lim}. If you prefer to redefine the original, \let\lim\relax \DeclareMathOperator*{\lim}{Lim} Sep 26 at 20:14

3 Answers 3


You can add \ShowCommand\lim to your preamble to see the definition of \lim. It'll show

> \lim=robust macro:
->\protect \lim  .

> \lim =\long macro:
->\mathop {\operator@font lim}.
<argument> \lim  
l.3 \ShowCommand\lim

You can then define something similar for \Lim or redefine \lim accordingly:

\NewDocumentCommand{\Lim}{}{\mathop{\operator@font Lim}}% Similar to \lim
\RenewDocumentCommand{\lim}{}{\mathop{\operator@font Lim}}% Replace \lim (lim -> Lim)

Note that this default definition differs from how its defined by other packages. For example, with amsmath, the definition is

> \lim=\protected macro:
->\qopname \relax m{lim}.
<argument> \lim 
l.4 \ShowCommand\lim

where \qopname takes 3 arguments, the first of which is the operator text. You could


Best would be to use other tools (like mathtools), which help you define operators in a natural way:


\let\lim\relax% Remove existing \lim definition
\DeclareMathOperator*{\lim}{Lim}% (Re)define \lim
\DeclareMathOperator*{\Lim}{Lim}% Define \Lim

Here's a complete minimal example:

enter image description here



%\NewDocumentCommand{\Lim}{}{\mathop{\operator@font Lim}}
%\RenewDocumentCommand{\lim}{}{\mathop{\operator@font Lim}}




  \lim_{n \rightarrow \infty} S_n
  \Lim_{n \rightarrow \infty} S_n


You can either define a new \Lim or redefine the existing \lim. Both are shown in this MWE.

$ \lim_{n\rightarrow\infty} S_n = \Lim_{n\rightarrow 0} Z_n$

\[ \lim_{n\rightarrow\infty} S_n = \Lim_{n\rightarrow 0} Z_n\]

enter image description here


The simplest way is to use amsmath (of course you already have it in a math document) and do


This is (slightly) less efficient than doing

\let\lim\relax %%% undefine \lim

See also How to redefine a command using \DeclareMathOperator

Another strategy is, of course, to do


and to use \Lim.

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