w2(z)=z1-cF(a-c+1,b-c+12-c;z)=z1-c(1-z)c-a-bF(1-a,1-b2-c;z)=z1-c(1-z)c-a-1F(a-c+1,1-b2-c;zz-1)=z1-c(1-z)c-b-1F(1-a,b-c+12-c;zz-1).