stochastic process, matlab to maths?

Can someone tell me, how to write this in mathematical form?

I am trying to understand it but I can't so may be I will understand from mathematical form.

I think it is something related to stochastic process.

for pointer_l = 0: (L-1)
            for pointer_t = 0: (T-t-1)
                scenarios(pointer_l*N+1: pointer_l*N+N, pointer_t*2+3: pointer_t*2+4) = ...
                round(unifrnd(1, WIDTH, N, 2));
            end
        end

Thanks in advance.