Decomposition of real number into elements of null measure sets

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Are there sets A and B such that any $x \in \mathbb{R}$ can be decomposed as $x = a+b$, $a \in A$ and $b \in B$, where the Lebesgue measure of $A$ and of $B$ is null.

There is an indication that this should follow from the fact that $C_q = \{z \in[0,1]; z_i\in\{0,2,\cdots,q-1\}\}$ has null measure for every $q \in \mathbb{N}$, where $z_i$ are the numbers in the q-adic expansion of $z$, that is $$z=\sum_{i=1}^{\infty}\frac{z_i}{q^i}$$

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Yes. The following example was given here by Davide Giraudo.

If $A$ is the set of real numbers such that in their proper binary expansion, the even terms are $0$, and $B$ the same with odd numbers, then $A$ and $B$ have measure $0$ but their sum is the whole real line

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Consider the classical cantor set $C$, then $$C-C = \{x-y\mid x,y\in C\} = [-1,1]$$