[This question is an extension of my question http://mathoverflow.net/questions/210316/does-a-positive-measure-subset-of-the-unit-interval-almost-surely-intersect-a-ra. I'm asking it to help me solve my question http://mathoverflow.net/questions/199540/do-the-birkhoff-averages-of-a-measurable-stationary-homogeneous-markov-process-i. ] >>Does there exist a measurable function $F\colon [0,1]^{\mathbb{Q}\cap [0,1]} \to [0,1]$ with the property that for every measurable $f\colon [0,\infty) \to [0,1]$, for Lebesgue-almost all $\tau \geq 0$ we have $$ \int_\tau^{\tau+1} f(t) \, dt \ = \ F\left( \, (f(\tau+q))_{q \in \mathbb{Q}\cap [0,1]} \, \right) \ ? $$ Given all the results to the effect that "measurable objects are approximately topological objects", it seems highly intuitive that the answer should be *yes*. In fact, it even seems intuitive to me that the function $$ F\left( \, (r_q)_{q \in \mathbb{Q}\cap [0,1]} \, \right) \ := \ \limsup_{n \to \infty} \, \frac{1}{2^n} \sum_{k=0}^{2^n-1} r_{\!\frac{k}{2^n}} $$ should work, but I have not managed to prove it.