Unsolved problem in mathematics:
Are graphs uniquely determined by their subgraphs?
Informally, the reconstruction conjecture in graph theory says that graphs are determined uniquely by their subgraphs. It is due to Kelly[1] and Ulam.[2][3]
- ^ Kelly, P. J., A congruence theorem for trees, Pacific J. Math. 7 (1957), 961–968.
- ^ Ulam, S. M., A collection of mathematical problems, Wiley, New York, 1960.
- ^ O'Neil, Peter V. (1970). "Ulam's conjecture and graph reconstructions". Amer. Math. Monthly. 77 (1): 35–43. doi:10.2307/2316851. JSTOR 2316851.