The algorithm JOIN seems to be incorrect

Question

Hi,

I have a problem with the command JOIN. I typed the following

{m,n,p,q}::Indices;
\Gamma_{#}::GammaMatrix(metric=g);

ex:= \Gamma_{mn} \Gamma_{p};

and when I applied the algorithm JOIN: join_gamma(ex) I got

\Gamma_{mnp} + g_{mnp}

I do not know what it is happening. Do you have any idea to solve this problem?

Thanks,

Answer 1

You need to separate index names by a space,

{m,n,p,q}::Indices;
\Gamma_{#}::GammaMatrix(metric=g);
ex:= \Gamma_{m n} \Gamma_{p};
join_gamma(_);