w3(z)=F(a,ba+b-c+1;1-z)=z1-cF(a-c+1,b-c+1a+b-c+1;1-z)=z-aF(a,a-c+1a+b-c+1;1-1z)=z-bF(b,b-c+1a+b-c+1;1-1z).