The determinant G(f_1, f_2, ..., f_n) = left bracketing bar integral f_1^2 d t | integral f_1 f_2 d t | ... | integral f_1 f_n d t integral f_2 f_1 d t | integral f_2^2 d t | ... | integral f_2 f_n d t ⋮ | ⋮ | ⋱ | ⋮ integral f_n f_1 d t | integral f_n f_2 d t | ... | integral f_n^2 d t right bracketing bar .

Gram-Schmidt orthonormalization | Wronskian