9 votes
Accepted

For any two non-isomorphic graphs $G, H$, does there exist a polysize, polylog quantifier depth first order formula which witnesses this?

Thanks to my colleague Maxim Zhukovskii for suggesting this answer. It turns out that the answer is negative, and the counterexample is rather simple. Just take $G=K_m\sqcup \overline{K_m}$ and $H=K_{...
Daniil Musatov's user avatar
3 votes
Accepted

In depth reduction of arithmetic formula why we get a $v$ st $\frac{s}3\leq |\Phi_v|\leq \frac{2s}{3}$

You do not cite the part of the survey that is actually relevant for getting the $s/3$ lower bound: Starting from the root, walk down to the leaves by always taking the child with a larger sub-tree ...
holf's user avatar
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