Zdroj TeX:

\small [{\pmb {e_1}, \pmb {e_2}, \cdot \cdot \cdot, \pmb {e_i}}] = [{\pmb {u_1}, \pmb {u_2}, \cdot \cdot \cdot, \pmb {u_i}}], ∀i ∈ {1, 2, . . . , k}