The following codes
{t,x,y,z,r}::Coordinate; \delta{#}::KroneckerDelta. {i,j,k,l,m,n,o,p,q,s#}::Indices(fourD,values={t,x,y,z},position=independent); {i,j,k,l,m,n,o,p,q,s#}::Integer(range=0..3) xx:=\delta^1_1^2_2; evaluate(_);
give me the ouput :
0
But, in my opinion I should get the value 1/2.
Further, I run
xx2:=\delta^1_1^2_2; expand_delta(_); eliminate_kronecker(_); evaluate(_);
at last, I get
RuntimeError: evaluate: Index 1 does not have an Indices property. At: Notebook Cell (Line 1): _ = evaluate(_); display(_)