4. Let x1,x2,y1,y2,z1,z2 be transcendental numbers. Suppose that any 3 of them are algebraically independent, and among the 15 four-tuples on {x1,x2,y1,y2}, {x1,x2,z1,z2} and {y1,y2,z1,z2} are algebraically dependent. Prove that there exists a transcendental number t that depends algebraically on each of the pairs {x1,x2} , {y1,y2}, and {z1,z2}. (A.37)
[L. Lovász] college conteststranscendental