Take the 2-minute tour ×
TeX - LaTeX Stack Exchange is a question and answer site for users of TeX, LaTeX, ConTeXt, and related typesetting systems. It's 100% free, no registration required.

I am working on a document, and in only one case have the \left and \right before my parentheses seemed to do anything. For example, I have this equation:

\begin{equation} \mathbb{E}(RS_{nd}) = (1-F(p_k + g^*(\tau, k\tau)))^{k-1}\left(\left(\left(1-PR[S]\right)+PR[S]\left(1-F\left(\hat{p}_k\right)\right)\right)\left(p_k-c\right)\right) \end{equation}

and it produces this output enter image description here

Why aren't the parenthesis displayed in different sizes? I am sorry for the long equation -- it seems to be mostly a problem in my longer equations. All the parentheses seem to match up with each other. Any ideas? T

share|improve this question
2  
\left and \right adjust in size to fit their content. Each of your expressions (appear as though they) are the same size, so there is no need for the () to adjust their size –  cmhughes Jan 10 '12 at 3:27
1  
it's really not a great idea to put \left and \right on the innermost delimiters when what's inside isn't larger than the base size. the last \left(p\_k-c\right) is one example of this. –  barbara beeton Jan 10 '12 at 13:37
    
@barbarabeeton: Apart from being unnecessary, is there any problem with it? –  celtschk Jan 10 '12 at 17:28
    
@celtschk -- if \left and \right are always properly matched, there shouldn't be any problem in the output. but if the file has to be edited for any reason, extra care has to be taken to make sure that nothing becomes unbalanced. this could definitely cause headaches for the production staff (and possibly introduce errors) if a file is submitted to and accepted for publication in a journal. –  barbara beeton Jan 10 '12 at 20:08
add comment

2 Answers

up vote 11 down vote accepted

Because the interior expressions are not larger than the default size. If you want to use enlarged parentheses in this way, you might try \bigl(...\bigr) and its cousins with \Big, \bigg, and \Bigg. Though some might say that for readability, you should also use different types of delimiters.

share|improve this answer
add comment

Normally TeX stretches \left and \right to be just a bit shorter than the contained content to avoid stuff exploding too much, but for this kind of expression you probably want it to expand to be a a bit bigger, to make delimiters at least 10% bigger than the content add

\delimiterfactor=1100

eg in the document preamble

which is a bit much, but you can reduce to taste

share|improve this answer
    
You mean the internet has been lying to me all these years about needing \bigl? –  Ryan Reich Jan 10 '12 at 19:36
1  
xkcd.com/386 –  David Carlisle Jan 12 '12 at 16:48
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.