 f C ⁢ 0 ⁡ ( x ) = l ^ 0 ⁡ ( ∑ i = 0 N ⁢ 0 N ⁢ D ⁡ ( i , x ) ⁢ l 0 ⁡ ( P ^ ι ⁡ ( u * , v * ) ) P ^ ι ⁡ ( u * , v * ) ⁢ P ^ ι ⁡ ( u * , v * ) ) f C ⁢ 0 ⁡ ( x ) = l ^ 0 ⁡ ( ∑ i = 0 N ⁢ 0 N ⁢ D ⁡ ( i , x ) ⁢ l 0 ⁡ ( P ^ ι ⁡ ( u * , v * ) ) P ^ ι ⁡ ( u * , v * ) ⁢ P ^ ι ⁡ ( u * , v * ) ) 