... subgraphs of hypercubes, J. Graph Theory 17 (1993), 477–479.[10] P. Erd˝os, O n extremal problems of graphs and generalized graphs, Israel J. Math. 2(1964), 183–190.[11] P. Erd˝os, On some problems ... edge formed by replacing bg(iℓ) in f(u) with a flip-bit is in G. But this edge is just theedge between f(u) and f(v). We therefore have an embedding of H in G, completing theproof. ✷To complete ... let ex(Qn, H) be the maximum numb er of edges in a su bgraph of Qnwhichdoes not contain a copy of H. We find a w ide class of subgraphs H, includingall previously known examples, for which...