∫02⁢πhcpm1⁡(x,ξ)⁢hcpm2⁡(x,ξ)⁢ⅆ⁡x=∫02⁢πhspm1⁡(x,ξ)⁢hspm2⁡(x,ξ)⁢ⅆ⁡x=0.