Morse-Sard theorem for d.c. curves
  Let $f:I\to X$ be a d.c. mapping, where $I\subset \R$ is an open interval and $X$ a Banach space. Let $C_f$ be the set of critical points of $f$.   We prove that $f(C_f)$ has zero 1/2-dimensional Hausdorff measure. 
D.Pavlica