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Erdős problem 907

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Let f:R→Rf:\mathbb{R}\to \mathbb{R} be such that f(x+h)−f(x)f(x+h)-f(x) is continuous for every h>0h>0. Is it true that f=g+hf=g+h for some continuous gg and additive hh (i.e. h(x+y)=h(x)+h(y)h(x+y)=h(x)+h(y))?

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  2. StatementRetained
  3. Formal1 retained
  4. Resolutionproved (Lean)
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  6. DecisionNone here
  7. The questionNot reached
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