# British maths style guide

For British maths style, is this punctuation OK?

so if $x=-3$, then $\left|x\right|=3$, and if $x=7$, then $\left|x\right|=7$, etc

with commas before "then" and "and".

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This might rather be an English language question ... –  Hagen von Eitzen May 31 '13 at 19:32
It’s perfectly acceptable punctuation, U.K. or U.S. Some might omit the commas before then; I would not. –  Brian M. Scott May 31 '13 at 20:14
This is a completely acceptable and even very welcome question for this site. Great mathematicians like Halmos, Steenrod, Serre and many others have written books or articles in mathematical journals (not in linguistics journals!) and given talks to mathematical audiences on the proper style and grammar of mathematical texts. Moreover, many users do not have English as their mother tongue and their wish to write that foreign language as correctly as possible should be lauded and not met with a scornful off topic closure. I encourage users to vote for reopening this fine question. –  Georges Elencwajg May 31 '13 at 21:23
I agree that this question would be better suited for English Language stack exchange (which lives for these types of context-specific grammar questions) but I will not unilaterally migrate it. Instead, I suggest that you crosspost there (or flag for migration) if you do not receive an adequate answer here. –  Alexander Gruber May 31 '13 at 21:29
Thanks for that. I did feel a bit deflated when my question was so quickly closed for being off topic. I'm not sure about the correct terminology but, to me, my example looks like two independent clauses joined by an 'and'. My grammar textbook tells me in that case there should be a comma before the 'and'. I wondered if the same rule applied to maths. With hindsight I guess there's no reason why, in this case, there should be any difference between UK or US punctuation. –  Peter4075 Jun 5 '13 at 20:12