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Feb 11, 2011 at 20:22 comment added Chulumba @Todd, thanks. So,there are many types of counterexample functions.
Feb 10, 2011 at 2:13 vote accept Chulumba
Feb 9, 2011 at 17:00 comment added Todd Trimble Chulumba, it's not hard if you know how to construct bump functions. You can take $F(R) = G(R) = [0, 1]$, and say $supp(F) = [2, 3]$ and $supp(G) = [3, 4]$, as follows. Define f(x) = exp(-1/x)exp(1/(1-x)) for 1 > x > 0, then g(x) = f(x)/(1 + f(x)) for 1 > x > 0, then define a continuous function h(x) piecewise to be = 0 for 0 > x, = g(3x) for 1/3 > x > 0, = 1 for 2/3 > x > 1/3, g(3-3x) for 1 > x > 2/3, and 0 for x > 1. Finally, define F(x) = h(x-2), and G(x) = h(x-3).
Feb 1, 2011 at 15:07 comment added Chulumba @Ady, thanks. I found it hard to find sample functions such that $supp\: F\cap G\left(\mathbb{R}\right)=supp\: G\cap F\left(\mathbb{R}\right)=\emptyset$. Could you come up with explicit two functions?
Jan 30, 2011 at 11:20 history answered Ady CC BY-SA 2.5