symsum and subscript. confirmation regarding limit for sum

Hi Folks,

I check the forum, and I see in the answers that subscript for variable that inside a sum term can not be a symbolic. But I just want confirm the code below.

I can't use n as symbolic variable simularly in example below.

Note i just it just index.

syms h(x)

n = 3;

syms k real positive

x = [sym('x_0'), sym('y_%d', [1, n])];

y = [sym('x_0'), sym('y_%d', [1, n])];

1-k/2 * n * symsum(1/k * (y(n).*log(h(x(n))) + (1-y(n)).*log(h(x(n)))), 1, n)

Thank you