∫abⅇⅈ⁢x⁢t⁢q⁡(t)⁢ⅆ⁡t∼ⅇⅈ⁢a⁢x⁢∑s=0∞q(s)⁡(a)⁢(ⅈx)s+1-ⅇⅈ⁢b⁢x⁢∑s=0∞q(s)⁡(b)⁢(ⅈx)s+1,