The Morse–Sard theorem in Wn,n(Ω): A simple proof

We give a simpler and more self-contained proof of the Morse–Sard theorem in the setting of Sobolev space Wn,n(Rn,R) with n⩾2, we already proved in a previous paper [R. van der Putten, The Morse–Sard theorem for Sobolev spaces in a borderline case, Bull. Sci. Math. 136 (4) (2012) 463–475, http://dx.doi.org/10.1016/j.bulsci.2010.02.001].