[Reduce-algebra-developers] Error with Physop packet

[abpetrov <abp...@uf...>]

Hi,

I tried use Physop packet for some calculations.
The simplified program looks like that

load_package noncom2;
load_package physop;

tensop l(2);
physindex s1,s2;
expr2 := l(s1,s2,x);
expr3 := sum( l(s1,s2,x),x);

Expression expr2 calculates as normal
At calculation of expr3 I got error

Declare l operator?

Why Reduce do it? And how correct it?

Best regards, Petrov Alexander.