Name: Vladyslav Shtabovenko (email_not_shown)
Date: 12/18/14-06:49:56 PM Z


Well, in principle there are infinitely many ways to obtain wrong
results by using wrong syntax, so it would take a lot of work to put
warning signs around all potential pitfalls.

But at least in your case it shouldn't be that difficult to catch
missing dots. So I added this to the development version

<https://github.com/FeynCalc/feyncalc/commit/bff5ac64a6fb909a6be5610d7a2094a58b4fa86a>

It is not a silver bullet and is very basic, but at least things like

TR[GA[a]GA[b]GA[c]GA[d]] or TR[GA[a,b]GA[c,d]] or TR[GA[a,b]GA[c]]

now generate

DiracTrace::noncom: Wrong syntax! The Dirac trace of xxx
contains Dirac matrices multiplied via Times (commutative
multiplication) instead of DOT (non-commutative multiplication).
Evaluation aborted!

Hope that helps.

Cheers,
Vladyslav

On 18/12/14 14:45, Sam wrote:
> Thanks very much for your help. Sometimes I do put in the dots and sometimes I don't, and I didn't realize it was so crucial. It is a little worrisome that there is no error message: it evaluates either way, but sometimes with the wrong answer.
>
> Anyway, thanks again for your help,
> Sam
>



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