F11⁡(a+ⅈ⁢x2⁢ℜ⁡a;-ⅈ⁢z)⁢F11⁡(b¯-ⅈ⁢x2⁢ℜ⁡b;ⅈ⁢z)=∑n=0∞pn⁡(x;a,b,a¯,b¯)(2⁢ℜ⁡a)n⁢(2⁢ℜ⁡b)n⁢zn.