Sorting terms with different indix names

[FeelUsM]

I often have expressions like A(mu,nu)B(mu,nu)+A(nu,mu)B(nu,mu). How to tell form that this is the same term, and how to do form to add this terms?

I ask my question here because my account on forum has not been activated yet.

Thanks, Philipp

[vermaseren]

You can look at the sum statement. You should issue the command sum mu,nu;

Jos

On 8 jun. 2017, at 20:19, Feel notifications@github.com wrote:

I often have expressions like A(mu,nu)B(mu,nu)+A(nu,mu)B(nu,mu). How to tell form that this is the same term, and how to do form to add this terms?

I ask my question here because my account on forum has not been activated yet.

Thanks, Philipp

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[tueda]

A concrete example:

I mu,nu;
CF A,B;
L F = A(mu,nu)*B(mu,nu)+A(nu,mu)*B(nu,mu);
P;
.sort
Sum mu,nu;
P;
.end

FORM 4.1 (Jun  8 2017, v4.1-20131025-351-g31c5798) 64-bits  Run: Thu Jun  8 20:26:08 2017

   F =
      A(mu,nu)*B(mu,nu) + A(nu,mu)*B(nu,mu);

   F =
      2*A(N1_?,N2_?)*B(N1_?,N2_?);