PUZZLE: Can you find a smooth (C^oo) function f : D -> [0,1] (where D is the closed unit disk in R^2) such that 1) f is onto. 2) The unit circle bd(D) is finv(1), and 3) For 0 < c <= 1, finv(c) is a smooth curve with length = 2pi. where finv(c) denotes the inverse image of c. --Dan _____________________________________________________________________ "It don't mean a thing if it ain't got that certain je ne sais quoi." --Peter Schickele