sin(π(c-a-b))πF(a,bc;z)=z-aΓ(c-a)Γ(c-b)F(a,a-c+1a+b-c+1;1-1z)-(1-z)c-a-bza-cΓ(a)Γ(b)F(c-a,1-ac-a-b+1;1-1z),