Let f be a function from to such that:
Uf = {(x,y): 0 < y< f(x)} is a measurable set in
The following I am copying exactly as I have it in my notes:
Suppose a > 1
Let = {(x, y-a): f(x) > a, 0 < y < (f(x) -a)/d and 0 < y < 1}
Show is measurable for all d>0
I think it's because:
is a translation Uf ((a, a+d)X ), which is measurable.
Any thoughts