Whitehead aspherical conjecture via ribbon sphere-link

Whitehead aspherical conjecture says that every connected subcomplex of every aspherical 2-complex is aspherical. By an argument on ribbon sphere-links, it is confirmed that the conjecture is true for every contractible finite 2-complex. In this paper, by generalizing this argument, this conjecture is confirmed to be true for every aspherical 2-complex.